Shallow Thoughts : tags : laptop

Limiting Battery Charge on a Lenovo Carbon X1

Ever since I got my Lenovo Carbon X1, I've wished there was some way to limit the battery charge. I keep it plugged in to a USB hub and external monitor most of the time, which means that the battery is at 100% for weeks on end. That isn't particularly good for lithium ion batteries: it's better for battery life to stop charging at around 80%.

Lots of laptops, including Dells and Apples, have a charge limit feature in their BIOS, but I searched through the CX1's BIOS several times and never found anything, so I'd resigned myself.. But just this week I accidentally stumbled on a way to set this at runtime!

Read more ...

Tags: linux, laptop, lenovo
[ 16:17 Nov 12, 2022    More linux/laptop | permalink to this entry | ]

Activate the Microphone on a Lenovo Carbon X1 Running Debian

When I bought my Carbon X1 laptop a few years ago, the sound card was new and not yet well supported by Linux. (I knew that before I bought, and decided it was a good gamble that support would improve soon.)

Early on, there was a long thread on Lenovo's forum discussing, in particular, how to get the microphone working. The key, apparently, was the SOF (Sound Open Firmware) support, which was standard in the 5.3 Linux kernel that came with Ubuntu 10.10, but needed an elaborate script to get working in earlier kernels.

It worked fine on Ubuntu. But under Debian, the built-in mic didn't work.

Read more ...

Tags: linux, laptop
[ 11:15 Mar 20, 2022    More linux/laptop | permalink to this entry | ]

Screen Brightness on an Asus 1015e (and other Intel-based laptops)

When I upgraded my Asus laptop to Stretch, one of the things that stopped working was the screen brightness keys (Fn-F5 and Fn-F6). In Debian Jessie they had always just automagically worked without my needing to do anything, so I'd never actually learned how to set brightness on this laptop. The fix, like so many things, is easy once you know where to look.

It turned out the relevant files are in /sys/class/backlight/intel_backlight. cat /sys/class/backlight/intel_backlight/brightness tells you the current brightness; write a number to /sys/class/backlight/intel_backlight/brightness to change it.

That at least got me going (ow my eyes, full brightness is migraine-inducing in low light) but of course I wanted it back on the handy function keys.

I wrote a script named "dimmer", with a symlink to "brighter", that goes like this:

#!/bin/zsh

curbright=$(cat /sys/class/backlight/intel_backlight/brightness)
echo dollar zero $0
if [[ $(basename $0) == 'brighter' ]]; then
  newbright=$((curbright + 200))
else
  newbright=$((curbright - 200))
fi
echo from $curbright to $newbright

sudo sh -c "echo $newbright > /sys/class/backlight/intel_backlight/brightness"

That let me type "dimmer" or "brighter" to the shell to change the brightness, with no need to remember that /sys/class/whatsit path. I got the names of the two function keys by running xev and typing Fn and F5, then Fn and F6. Then I edited my Openbox ~/.config/openbox/rc.xml, and added:

<keybind key="XF86MonBrightnessDown">
  <action name="Execute">
    <execute>dimmer<execute>
  </action>
</keybind>
<keybind key="XF86MonBrightnessUp">
  <action name="Execute">
    <execute>brighter<execute>
  </action>
</keybind>

Tags: linux, laptop
[ 19:57 Sep 17, 2017    More linux/laptop | permalink to this entry | ]

Trackpad workarounds: using function keys as mouse buttons

I've had no end of trouble with my Asus 1015E's trackpad. A discussion of laptops on a mailing list -- in particular, someone's concerns that the nifty-looking Dell XPS 13, which is available preloaded with Linux, has had reviewers say that the trackpad doesn't work well -- reminded me that I'd never posted my final solution.

The Asus's trackpad has two problems. First, it's super sensitive to taps, so if any part of my hand gets anywhere near the trackpad while I'm typing, suddenly it sees a mouse click at some random point on the screen, and instead of typing into an emacs window suddenly I find I'm typing into a live IRC client. Or, worse, instead of typing my password into a password field, I'm typing it into IRC. That wouldn't have been so bad on the old style of trackpad, where I could just turn off taps altogether and use the hardware buttons; this is one of those new-style trackpads that doesn't have any actual buttons.

Second, two-finger taps don't work. Three-finger taps work just fine, but two-finger taps: well, I found when I wanted a right-click (which is what two-fingers was set up to do), I had to go TAP, TAP, TAP, TAP maybe ten or fifteen times before one of them would finally take. But by the time the menu came up, of course, I'd done another tap and that canceled the menu and I had to start over. Infuriating!

I struggled for many months with synclient's settings for tap sensitivity and right and left click emulation. I tried enabling syndaemon, which is supposed to disable clicks as long as you're typing then enable them again afterward, and spent months playing with its settings, but in order to get it to work at all, I had to set the timeout so long that there was an infuriating wait after I stopped typing before I could do anything.

I was on the verge of giving up on the Asus and going back to my Dell Latitude 2120, which had an excellent trackpad (with buttons) and the world's greatest 10" laptop keyboard. (What the Dell doesn't have is battery life, and I really hated to give up the Asus's light weight and 8-hour battery life.) As a final, desperate option, I decided to disable taps completely.

Disable taps? Then how do you do a mouse click?

I theorized, with all Linux's flexibility, there must be some way to get function keys to work like mouse buttons. And indeed there is. The easiest way seemed to be to use xmodmap (strange to find xmodmap being the simplest anything, but there you go). It turns out that a simple line like

  xmodmap -e "keysym F1 = Pointer_Button1"

is most of what you need. But to make it work, you need to enable "mouse keys":

  xkbset m

But for reasons unknown, mouse keys will expire after some set timeout unless you explicitly tell it not to. Do that like this:

  xkbset exp =m

Once that's all set up, you can disable single-finger taps with synclient:

  synclient TapButton1=0

Of course, you can disable 2-finger and 3-finger taps by setting them to 0 as well. I don't generally find them a problem (they don't work reliably, but they don't fire on their own either), so I left them enabled.

I tried it and it worked beautifully for left click. Since I was still having trouble with that two-finger tap for right click, I put that on a function key too, and added middle click while I was at it. I don't use function keys much, so devoting three function keys to mouse buttons wasn't really a problem.

In fact, it worked so well that I decided it would be handy to have an additional set of mouse keys over on the other side of the keyboard, to make it easy to do mouse clicks with either hand. So I defined F1, F2 and F3 as one set of mouse buttons, and F10, F11 and F12 as another.

And yes, this all probably sounds nutty as heck. But it really is a nice laptop aside from the trackpad from hell; and although I thought Fn-key mouse buttons would be highly inconvenient, it took surprisingly little time to get used to them.

So this is what I ended up putting in .config/openbox/autostart file. I wrap it in a test for hostname, since I like to be able to use the same configuration file on multiple machines, but I don't need this hack on any machine but the Asus.

if [ $(hostname) == iridum ]; then
  synclient TapButton1=0 TapButton2=3 TapButton3=2 HorizEdgeScroll=1

  xmodmap -e "keysym F1 = Pointer_Button1"
  xmodmap -e "keysym F2 = Pointer_Button2"
  xmodmap -e "keysym F3 = Pointer_Button3"

  xmodmap -e "keysym F10 = Pointer_Button1"
  xmodmap -e "keysym F11 = Pointer_Button2"
  xmodmap -e "keysym F12 = Pointer_Button3"

  xkbset m
  xkbset exp =m
else
  synclient TapButton1=1 TapButton2=3 TapButton3=2 HorizEdgeScroll=1
fi

Tags: linux, laptop, trackpad, synaptics, synclient, syndaemon, xmodmap
[ 20:54 Jul 26, 2015    More linux | permalink to this entry | ]

Laptop-mode interferes with remote presenter

While practicing a talk the other night on my new Asus laptop, my Logitech remote presenter, which had worked fine a few hours earlier, suddenly became flaky. When I clicked the "next slide" button, sometimes there would be a delay of up to ten seconds; sometimes it never worked at all, and I had to click it again, whereupon the slide might advance once, twice, or not at all. Obviously not useful.

Realizing that I'd been plugged into AC earlier in the day, and now was running on battery, I plugged in the AC adaptor. And sure enough, the presenter worked fine, no delays or glitches. So battery was the issue.

What's different about running on batteries? I immediately suspected laptop-mode, which sets different power profiles to help laptops save battery life when unplugged.

The presenter acts as a USB keyboard, sending key events like PAGE DOWN, and on other distros (specifically Arch Linux) I've had problems with USB keyboard devices disappearing when laptop-mode is active.

So I moved /etc/init.d/laptop-mode out of the way to disable it, and rebooted. Tried the presenter again: no improvement.

But it was laptop-mode anyway. Apparently even though /etc/init.d/laptop-mode says in its header that its purpose is to start and stop laptop-mode, apparently laptop-mode starts even without that file. The key is the configuration file /etc/laptop-mode/conf.d/usb-autosuspend.conf, where I changed the line

CONTROL_USB_AUTOSUSPEND="auto"

to

CONTROL_USB_AUTOSUSPEND=0

In theory, I should have been able to do service laptop-mode restart to test it, but I didn't trust that since I'd just established that /etc/init.d/laptop-mode didn't actually control laptop-mode. So I rebooted. And the presenter worked just fine! I was able to give my talk that afternoon without plugging in the AC cord.

Ironically, this particular talk was on giving tech talks, and one of my points was that being prepared and practicing beforehand is critical to giving a good talk. I'm sure glad I did that extra practice run with the presenter and no power cord!

Tags: linux, laptop, speaking
[ 16:13 Nov 03, 2013    More speaking | permalink to this entry | ]

How to enable/disable laptop wireless hardware

My Lenovo laptop has a nifty button, Fn-F5, to toggle wi-fi and bluetooth on and off. Works fine, and the indicator lights (of which the Lenovo has many -- it's quite nice that way) obligingly go off or on.

But when I suspend and resume, the settings aren't remembered. The machine always comes up with wireless active, even if it wasn't before suspending.

Since wireless can be a drain on battery life, as well as a potential security issue, I don't want it on when I'm not actually using it. So I wanted a way to turn it off programmatically.

The answer, it turns out, is rfkill.

$ rfkill list
0: tpacpi_bluetooth_sw: Bluetooth
        Soft blocked: yes
        Hard blocked: no
0: phy0: Wireless LAN
        Soft blocked: yes
        Hard blocked: no

tells you what hardware is currently enabled or disabled.

To toggle something off,

$ rfkill block bluetooth
$ rfkill block wifi

Type rfkill -h for more details on arguments you can use.

Fn-F5 still works to enable or disable them together. I think this is being controlled by /etc/acpi/ibm-wireless.sh, though I can't find where it's tied to Fn-F5.

You can make it automatic by creating /etc/pm/sleep.d/. (That's on Ubuntu; of course, the exact file location may vary with distro and version.) To disable wireless on resume, do this:

#! /bin/sh

case "$1" in
  resume)
    rfkill block bluetooth
    rfkill block wifi
    ;;
esac
exit $?

Of course, you can also tie that into other things, like your current network scheme, or what wireless networks are visible (which you can get with iwlist wlan0 scan).

Tags: linux, ubuntu, laptop, tip
[ 19:46 Mar 04, 2013    More linux/laptop | permalink to this entry | ]

Touchpad and trackball blues: Emulate the middle button, and touchpad disable

In setting up a laptop -- Debian "Squeeze" with a Gnome 2 desktop -- for an invalid who will be doing most of her computing from bed, we hit a snag. Two snags, actually: both related to the switching between the trackpad and an external trackball.

Disabling and re-enabling the trackpad

First, the trackpad gets in the way when she's typing. "Disable touchpad while typing" was already set, but it doesn't actually work -- the mouse was always moving when her palm brushed against it.

On her desktop computer, she's always used a Logitech trackball -- never really got the hang of mice, but that trackball always worked well for her. And fortunately, unlike a mouse, a trackball works just fine from bed.

Once the trackball is working, there's really no need to have the trackpad enabled. So why not just turn it off when the external trackball is there? I thought I'd once seen a preference like that ... but it was nowhere to be found in the Gnome 2 desktop.

It turns out the easiest way to disable a trackpad is this:

synclient TouchpadOff=1

Using 0 instead of 1 turns it back on. So we gave her shell aliases for both these commands. A web search will show various approaches to writing udev rules to run something like that automatically, but she felt it was easy enough to type a command when she switches modes, so we're going with that for now.

Emulate the middle button on an external mouse or trackball

We thought we were done -- until we tried to paste that alias into her shell and discovered that 2-button paste doesn't work for external mice in Squeeze.

Usually, when you have a mouse-like device that has only two buttons, you can click the left and right buttons together to emulate a middle click. She'd been using that on her old Ubuntu Lucid install, and it works on pretty much every trackpad I've used. But it didn't work with the USB trackball on Squeeze.

Gnome used to have a preference for middle button emulation, but it's gone now. There's a program you can install called gpointing-device-settings that offers a 2-button emulation setting ... but it doesn't save the settings anywhere. And since it's a GUI program you can't make it part of your login or boot process -- you'd have to go through and click to set it every time. Not happening.

2-buttom emulation is an X setting -- one of the settings that used to be specified in Xorg.conf, and now wanders around to different places on every distro. A little web searching didn't turn up a likely candidate for Squeeze, but it did turn up a way that's probably more distro independent: the xinput command.

After installing xinput, you need the X ID of the external mouse or trackball. xinput list should show you something like this (plus more stuff for keyboards and possibly other devices):

$ xinput list
  Virtual core pointer                          id=2    [master pointer  (3)]
      Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
      SynPS/2 Synaptics TouchPad                id=10   [slave  pointer  (2)]
      Kensington Kensington USB/PS2 Orbit       id=13   [slave  pointer  (2)]

Once you have the id of the external device, list its properties:

$ xinput list-props 13                                       ~ 9:01PM
Device 'Kensington Kensington USB/PS2 Orbit':
        Device Enabled (132):   1
  ... long list of other properties ...
        Evdev Middle Button Emulation (303):    0
        Evdev Middle Button Timeout (304):      50
  ... more properties ...

You can see that middle button emulation is disabled (0). So turn it on:

$ xinput --set-prop 13 "Evdev Middle Button Emulation" 1

Click both buttons together, and sure enough -- a middle button paste! I added that to the alias that turns the trackpad off -- though of course, it could also be added to a udev rule that fires automatically when the mouse is plugged in.

Tags: linux, laptop
[ 15:34 Sep 08, 2012    More linux/install | permalink to this entry | ]

Synaptics horizontal scrolling (and other touchpad configurations)

My new netbook (about which, more later) has a trackpad with areas set aside for both vertical and horizontal scrolling. Vertical scrolling worked out of the box on Squeeze without needing any extra fiddling. My old Vaio had that too, and I loved it.

Horizontal scrolling took some extra research. I was able to turn it on with a command:

synclient HorizEdgeScroll=1

(thank you, AbsolutelyTech). Then it worked fine, for the duration of that session.

But it took a lot more searching to find out the right place to set it permanently. Nearly every page you find on trackpad settings tells you to edit /etc/X11/xorg.conf. Distros haven't normally used xorg.conf in over three years! Sure, you can generate one, then edit it -- but surely there's a better way.

And there is. At least in Debian Squeeze and Ubuntu Natty, you can edit /usr/share/X11/xorg.conf.d/50-synaptics.conf and add this options line inside the "InputClass" section:

        options "HorizEdgeScroll" "1"

Don't forget the quotes, or X won't even start.

In theory, you can use this for any of the Synaptics driver options -- tap rate and sensitivity, even multitouch. Your mileage may vary -- horizontal scroll is the only one I've tested so far. But at least it's easier than generating and maintaining an xorg.conf file!

Tags: linux, X11, laptop
[ 16:20 Oct 31, 2011    More linux/laptop | permalink to this entry | ]

Of Laptops, Docking Stations and Changing Resolution

I've been setting up a new Lenovo X201 laptop at work. (Yes, work -- I've somehow fallen into an actual job where I go in to an actual office at least some of the time. How novel!)

At the office I have a Lenovo docking station, attached to a monitor and keyboard. The monitor, naturally, has a different resolution from the laptop's own monitor.

Under Gnome and compiz, when I plugged in the monitor, I could either let the monitor mirror the laptop display -- in which case X would refuse to work at greater than 1024x768, much smaller than the native resolution of either the laptop screen or the external monitor -- or I could call up the classic two-monitor configuration dialog, where I could configure the external monitor to be its correct size and sit alongside the computer's monitor. I had to do this every time I plugged in.

If I wanted to work on the big screen, then when I undocked, I had to drag all the windows on all desktops back to the built-in LCD first, or they'd be lost. Using just the external monitor and turning off the laptop screen didn't seem to be an allowed option.

That all lasted for about two days. Gnome and I just don't get along. Pretty soon gdm was mysteriously refusing to let me log in (probably didn't like my under-1000 user id), and after wasting half a day fighting it I gave up and reverted with relief to my familiar Openbox desktop.

But now I'm in the Openbox world and don't have that dialog anyway. What are my options?

xrandr monitor detection

Fortunately, I already knew about using xrandr to send to a projector; it was only a little more complicated using it for the monitor in the docking station. Running xrandr with no arguments prints all the displays it currently sees, so you can tell whether an external display or projector is connected and even what resolutions it supports.

I used that for a code snippet in my .xinitrc:

# Check whether the external monitor is connected: returns 0 on success
xrandr | grep VGA | grep " connected "
if [ $? -eq 0 ]; then
  xrandr --output VGA1 --mode 1600x900;
  xrandr --output LVDS1 --off
else
  xrandr --output VGA1 --off
  xrandr --output LVDS1 --mode 1280x800
fi

That worked nicely. When I start X it checks for an external monitor, and if it finds one it turns off the laptop display (so it's off when the laptop is sitting closed in the docking station) and sets the screen size for the external monitor.

Making it automatic

All well and good. I worked happily all day in the docking station, suspended the laptop and un-docked it, brought it home, woke it up -- and of course the display was still off. Oops.

Okay, so it also needs the same check when resuming from suspend. That used to be in /etc/acpi/resume.d, but in Lucid they've moved it (because we definitely wouldn't want users to get complacent and think they know how to configure things!) and now it lives in /etc/pm/sleep.d. I created a new file, /etc/pm/sleep.d/20_enable_display which looks like this:

#!/bin/sh

case "$1" in
    resume)
        # Check whether the external monitor is connected:
        # returns 0 on success
        xrandr | grep VGA | grep " connected "
        if [ $? -eq 0 ]; then
            xrandr --output VGA1 --mode 1600x900
            xrandr --output LVDS1 --off
        else
            xrandr --output VGA1 --off
            xrandr --output LVDS1 --mode 1280x800
        fi
        hsetroot -center `find -L $HOME/Backgrounds -name "*.*" | $HOME/bin/randomline`

        ;;
    suspend|hibernate)
        ;;
    *)
        ;;
esac
exit $?

Neat! Now, every time I wake from suspend, the laptop checks whether an external monitor is connected and sets the resolution accordingly. And it re-sets the background (using my random wallpaper method) so I don't get a tiled background on the big monitor.

Update: hsetroot -fill works better than -center given that I'm displaying background images on two different resolutions. Of course, if I wanted to get fancy I could make separate background sets, one for each monitor, and choose images from the appropriate set.

We're almost done. Two more possible adjustments.

Detecting undocking

First, while poking around in /etc/acpi I noticed a script named undock.sh. In theory, I can put the same code snippet in there, and then if I un-dock the laptop without suspending it first, it will immediately change resolution. I haven't actually tried that yet.

Projectors

Second, this business of turning off the built-in display if there's anything plugged into the VGA port is going to break if I use this laptop for presentations, since a projector will also show up as VGA1. So the code may need to be a little smarter. For example:

xrandr | grep VGA | grep " connected " | grep 16.0x

The theory here is that an external monitor will be able to do 1680 or 1600, so it will have a line like VGA1 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 434mm x 270mm. The 1680x matches the 16.0x pattern in grep. A projector isn't likely to do more than 1280, so it won't match the pattern '16.0x'. However, that isn't very robust; it will probably fail for one of those fancy new 1920x1080 monitors. You could extend it with

xrandr | grep VGA | grep " connected " | egrep '16.0x|19.0x'

but that's getting even more hacky ... and it might be time to start writing some more intelligent code.

Which doubtless I'll do if I ever get a 1920x1080 monitor.

Tags: linux, X11, laptop
[ 23:11 Sep 13, 2010    More linux/laptop | permalink to this entry | ]

Controlling brightness on a Sony laptop in Linux 2.6.31

My laptop, a Sony Vaio TX650P, badly needed a kernel update. 2.6.28.3 had been running so well that I just hadn't gotten around to changing it. When I finally updated to 2.6.31.5, nearly everything worked, with one exception: Fn-F5 and Fn-F6 no longer adjusted screen brightness.

I found that there were lots of bugs filed on this problem -- kernel.org bug 12816, Ubuntu bug 414810, Fedora bug 519105 and so on. A few of them had terse comments like "Can you try this patched binary release?" but none of them had a source patch, or any hints as to the actual nature of the problem.

But one of them did point me to /sys/class/backlight. In my working 2.6.28.3 kernel, that directory contained a sony subdirectory containing useful files that let me query or change the brightness: echo 1 >/sys/class/backlight/sony/brightness
On my nonworking 2.6.31.5 kernel, I had /sys/class/backlight but there was no sony subdirectory there.

grep SONY .config in the two kernels revealed that my working kernel had SONY_LAPTOP set, while the nonworking one did not. No problem! Just figure out where SONY_LAPTOP is in the configuration (it turns out to be at the very end of "device drivers" under "X86 Platform Specific Device Drivers"), make menuconfig, set SONY_LAPTOP and rebuild ... right?

Well, no. make menuconfig showed me lots of laptop manufacturers in the "Platform Specific" category, but Sony wasn't one of them. Of course, since it didn't show the option it also didn't offer a chance to read the help for the option either, which might have told me what its dependencies were.

Time for a recursive grep of kernel source: grep -r SONY_LAPTOP .
arch/x86/configs/i386_defconfig told me the option did indeed still exist, and where to find it. drivers/platform/x86/Kconfig lists the option itself, and says it depends on INPUT and RFKILL.

RFKILL? A bit more poking around located that one near the end of "Networking support", with the name "RF switch subsystem support". (I love how user-visible names for kernel options only marginally resemble the CONFIG names.) It's apparently intended for "control over RF switches found on many WiFi and Bluetooth cards," something I don't seem to need on this laptop (my WiFi works fine without it) -- except that the kernel for some reason won't let me build the ACPI brightness control without it.

So that's the secret. Go to "Networking support", set "RF switch subsystem support", then back up to "Device drivers", scroll down to the end to find "X86 Platform Specific Device Drivers" and inside it you'll now see "Sony Laptop Extras". Enable that, and the Fn-F5/F6 keys (as well as /sys/class/backlight/sony/brightness) will work again.

Tags: linux, kernel, sony, laptop
[ 10:07 Nov 02, 2009    More linux/kernel | permalink to this entry | ]

Updated Network Schemes page

I've used my simple network schemes setup for many years. No worries about how distros come up with a new network configuration GUI every release; no worries about all the bloat that NetworkManager insists on before it will run; no extra daemons running all the time polling my net just in case I might want to switch networks suddenly. It's all command-line based; if I'm at home, I type

netscheme home

and my network will be configured for that setup until I tell it otherwise. If I go to a cafe with an open wi-fi link, I type netscheme wifi; I have other schemes for places I go where I need a wireless essid or WEP key. It's all very easy and fast.

Last week for SCALE I decided it was silly to have to su and create a new scheme file for conferences where all I really needed was the name of the network (the essid), so I added a quick hack to my netscheme script so that typing netscheme foo, where there's no existing scheme by that name, will switch to a scheme using foo as the essid. Worked nicely, and that inspired me to update the "documentation".

I wrote an elaborate page on my network schemes back around 2003, but of course it's all changed since then and I haven't done much toward updating the page. So I've rewritten it completely, taking out most of the old cruft that doesn't seem to apply any more. It's here: Howto Set Up Multiple Network Schemes on a Linux Laptop.

Tags: linux, laptop, networking
[ 10:51 Feb 27, 2009    More linux/laptop | permalink to this entry | ]

Widescreen laptop for presentations

I've written before about how I'd like to get a netbook like an Asus Eee, except that the screen resolution puts me off: no one makes a netbook with vertical resolution of more than 600. Since most projectors prefer 1024x768, I'm wary of buying a laptop that can't display that resolution.

(What was wrong with my beloved old Vaio? Nothing, really, except that the continued march of software bloat means that a machine that can't use more than 256M RAM is hurting when trying to run programs (*cough* Firefox *cough) that start life by grabbing about 90M and goes steadily up from there. I can find lightweight alternatives for nearly everything else, but not for the browser -- Dillo just doesn't cut it.)

Ebay turned out to be the answer: there are lots of subnotebooks there, nice used machines with full displays at netbook prices. And so a month before LCA I landed a nice Vaio TX650 with 1.5G RAM, Pentium M, Intel 915GM graphics and Centrino networking. All nice Linux-supported hardware.

But that raised another issue: how do widescreen laptops (the TX650 is 1366x768) talk to a projector? I knew it was possible -- I see people presenting from widescreen machines all the time -- but nobody ever writes about how it works.

The first step was to get it talking to an external monitor at all. I ran a VGA cable to my monitor, plugged the other end into the Vaio (it's so nice not to need a video dongle!) and booted. Nothing. Hmm.

But after some poking and googling, I learned that with Intel graphics, xrandr is the answer:

xrandr --output VGA --mode 1024x768

switches the external VGA signal on, and

xrandr --auto

switches it back off.

Update, April 2010: With Ubuntu Lucid, this has changed and now it's
xrandr --output VGA1 --mode 1024x768
-- in other words, VGA changed to VGA1. You can run xrandr with no arguments to get a list of possible output devices and find out whether X sees the external projector or screen correctly.

Well, mostly. Sometimes it doesn't work -- like, unfortunately, at the lightning talk session, so I had to give my talk without visuals. I haven't figured that out yet. Does the projector have to be connected before I run xrandr? Should it not be connected until after I've already run xrandr? Once it's failed, it doesn't help to run xrandr again ... but a lot of fiddling and re-plugging the cable and power cycling the projector can sometimes fix the problem, which obviously isn't helpful in a lightning talk situation.

Eventually I'll figure that out and blog it (ideas, anyone?) but the real point of today's article is resolution. What I wanted to know was: what happened to that wide 1366-pixel screen when I was projecting 1024 pixels? Would it show me some horrible elongated interpolated screen? Would it display on the left part of the laptop screen, or the middle part?

The answer, I was happy to learn, is that it does the best thing possible: it sends the leftmost 1024 pixels to the projector, while still showing me all 1366 pixels on the laptop screen.

Why ... that means ... I can write notes for myself, to display in the rightmost 342 screen pixels! All it took was a little bit of CSS hacking in my HTML slide presentation package, and it worked fine. Now I have notes just like my Mac friends with their Powerpoint and their dual-head video cards, only I get to use Linux and HTML. How marvellous! I could get used to this widescreen stuff.

Tags: laptop, X11, linux, speaking, projector, lca2009, linux.conf.au
[ 22:12 Feb 06, 2009    More linux/laptop | permalink to this entry | ]

Open Letter to Asus and Other Netbook Manufacturers

Dear Asus, and other manufacturers who make Eee imitations:

The Eee laptops are mondo cool. So lovely and light. Thank you, Asus, for showing that it can be done and that there's lots of interest in small, light, cheap laptops, thus inspiring a bazillion imitators. And thank you even more for offering Linux as a viable option!

Now would one of you please, please offer some models that have at least XGA resolution so I can actually buy one? Some of us who travel with a laptop do so in order to make presentations. On projectors that use 1024x768.

So far HP is the only manufacturer to offer WXGA, in the Mini-Note. But I read that Linux support is poor for the "Chrome 9" graphics chip, and reviewers seem very underwhelmed with the Via C7 processor's performance and battery life. Rumours of a new Mini-Note with a Via Nano or, preferably, Intel Atom and Intel graphics chip, keep me waiting. C'mon, won't somebody else step up and give HP some competition?

It's so weird to have my choice of about 8 different 1024x600 netbook models under $500, but if I want another 168 pixels vertically, the price from everyone except HP jumps to over $2000.

Folks: there is a marketing niche here that you're missing.

Tags: tech, netbook, laptop, resolution, projector
[ 22:50 Oct 08, 2008    More tech | permalink to this entry | ]

Powertop BOF at Linuxworld 2007

The best thing at Linuxworld was the Powertop BOF, despite the fact that it ended up stuck in a room with no projector. The presenter, Arjan van de Ven, coped well with the setback and managed just fine.

The main goal of Powertop is to find applications that are polling or otherwise waking the CPU unnecessarily, draining power when they don't need to. Most of the BOF focused on "stupid stuff": programs that wake up too often for no reason. Some examples he gave (many of these will be fixed in upcoming versions of the software):

• gnome-screensaver checked every 2 sec to see if the mouse moved (rather than using the X notification for mouse move);
• gnome volume checked 10 times a second whether the volume has changed;
• gnome-clock woke up once a second to see if the minute had rolled over, rather than checking once a minute;
• firefox in an ssl layer polled 10 times a second in case there was a notification;
• the gnome file monitor woke up 40 times a second to check a queue even if there was nothing in the queue;
• evolution woke up 10 times a second;
• the fedora desktop checked 10 times a second for a smartcard;
• gksu used a 10000x/sec loop (he figures someone mistook milliseconds/microseconds: this alone used up 45 min on one battery test run)
• Adobe's closed-source flash browser plugin woke up 2.5 times a second, and acroread had similar problems (this has been reported to Adobe but it's not clear if a fix is coming any time soon).

And that's all just the desktop stuff, without getting into other polling culprits like hal and the kernel's USB system. The kernel itself is often a significant culprit: until recently, kernels woke up once a millisecond whether they needed to or not. With the recent "tickless" option that appeared in the most recent kernel, 2.6.22, the CPU won't wake up unless it needs to.

A KDE user asked if the KDE desktop was similarly bad. The answer was yes, with a caveat: Arjan said he gave a presentation a while back to a group of KDE developers, and halfway through, one of the developers interrupted him when he pointed out a problem to say "That's not true any more -- I just checked in a fix while you were talking." It's nice to hear that at least some developers care about this stuff! Arjan said most developers responded very well to patches he'd contributed to fix the polling issues.

(Of course, those of us who use lightweight window managers like openbox or fvwm have already cut out most of these gnome and kde power-suckers. The browser issues were the only ones that applied to me, and I certainly do notice firefox' polling: when the laptop gets slow, firefox is almost always the culprit, and killing it usually brings performance back.)

As for hardware, he mentioned that some linux LCD drivers don't really dim the backlight when you reduce brightness -- they just make all the pixels darker. (I've been making a point of dimming my screen when running off batteries; time to use that Kill-A-Watt and find out if it actually matters!) Wireless cards like the ipw100 use a lot of power even when not transmitting -- sometimes even more than when they're transmitting -- so turning them off can be a big help. Using a USB mouse can cut as much as half an hour off a battery. The 2.6.23 kernel has lots of new USB power saving code, which should help. Many devices have activity every millisecond, so there's lots of room to improve.

Another issue is that even if you get rid of the 10x/sec misbehavers, some applications really do need to wake up every second or so. That's not so bad by itself, but if you have lots of daemons all waking up at different times, you end up with a CPU that never gets to sleep.

The solution is to synchronize them by rounding the wakeup times to the nearest second, so that they all wake up at about the same time, and the CPU can deal with them all then go back to sleep. But there's a trick: each machine has to round to a different value. You don't want every networking application on every machine across the internet all waking up at once -- that's a good way to flood your network servers. Arjan's phrase: "You don't want to round the entire internet" [to the same value].

The solution is a new routine in glib: timeout_add_seconds. It takes a hash of the hostname (and maybe other values) and uses that to decide where to round timeouts for the current machine. If you write programs that wake up on a regular basis, check it out. In the kernel, round_jiffies does something similar.

After all the theory, we were treated to a demo of powertop in action. Not surprisingly, it looks a bit like top. High on the screen is summary information telling you how much time your CPU is spending in the various sleep states. Getting into the deeper sleep states is generally best, but it's not quite that simple: if you're only getting there for short periods, it takes longer and uses more power to get back to a running state than it would from higher sleep states.

Below that is the list of culprits: who is waking your CPU up most often? This updates every few seconds, much like the top program. Some of it's clear (names of programs or library routines); other lines are more obscure if you're not a kernel hacker, but I'm sure they can all be tracked down.

At the bottom of the screen is a geat feature: a short hint telling you how you could eliminate the current top offender (e.g. kill the process that's polling). Not only that, but in many cases powertop will do it for you at the touch of a key. Very nice! You can try disabling things and see right away whether it helped.

Arjan stepped through killing several processes and showing the power saving benefits of each one. (I couldn't help but notice, when he was done, that the remaining top offender, right above nautilus, was gnome-power-manager. Oh, the irony!)

It's all very nifty and I'm looking forward to trying it myself. Unfortunately, I can't do that on the laptop where I really care about battery life. Powertop requires a kernel API that went in with the "tickless" option, meaning it's in 2.6.22 (and I believe it's available as a patch for 2.6.21). My laptop is stuck back on 2.6.18 because of an IRQ handling bug (bug 7264). Powertop also requires ACPI, which I have to disable because of an infinite loop in kacpid (bug 8274, Ubuntu bug 75174). It's frustrating to have great performance tools like powertop available, yet not be able to use them because of kernel regressions. But at least I can experiment with it on my desktop machine.

Tags: linux, conferences, linuxworld, laptop, gnome
[ 14:06 Aug 12, 2007    More linux | permalink to this entry | ]

Desktop Suspend!

My laptop has always been able to sleep (suspend to RAM), one way or another, but I had never managed it on a desktop machine. Every time I tried running something like apm -s, apm -S, echo 3 >/sys/power/state, or Ubuntu's /etc/acpi/sleep.sh, the machine would sleep nicely, then when I resumed it would come up partway then hang, or would simply boot rather than resuming.

Dave was annoyed by it too: his Mac G4 sleeps just fine, but none of his Linux desktops could. And finally he got annoyed enough to spend half a day playing with different options. With what he learned, both he and I now have desktops that can suspend to RAM (his under Debian Sarge, mine under Ubuntu Edgy).

One step was to install hibernate (available as a deb package in both Sarge and Edgy, but distros which don't offer it can probably get it from somewhere on suspend2.net). The hibernate program suspends to disk by default (which is what its parent project, suspend2, is all about) but it can also suspend to RAM, with the following set of arcane arguments:

hibernate -v 4 -F /etc/hibernate/ram.conf

(the -v 4 adds a lot of debugging output; remove it once you have things working).

Though actually, in retrospect I suspect I didn't need to install hibernate at all, and Ubuntu's /etc/acpi/sleep.sh script would have done just as well, once I'd finished the other step:

Fiddle with BIOS options. Most BIOSes have a submenu named something like "Power Management Options", and they're almost always set wrong by default (if you want suspend to work). Which ones are wrong depends on your BIOS, of course. On Dave's old PIII system, the key was to change "Sleep States" to include S3 (S3 is the ACPI suspend-to-RAM state). He also enabled APM sleep, which was disabled by default but which works better with the older Linux kernels he uses under Sarge.

On my much newer AMD64 system, the key was an option to "Run VGABIOS if S3 Resume", which was turned off by default. So I guess it wasn't re-enabling the video when I resumed. (You might think this would mean the machine comes up but doesn't have video, but it's never as simple as that -- the machine came up with its disk light solid red and no network access, so it wasn't just the screen that was futzed.)

Such a simple fix! I should have fiddled with BIOS settings long ago. It's lovely to be able to suspend my machine when I go away for a while. Power consumption as measured on the Kill-a-Watt goes down to 5 watts, versus 3 when the machine is "off" (desktop machines never actually power off, they're always sitting there on standby waiting for you to press the power button) and about 75 watts when the machine is up and running.

Now I just have to tweak the suspend scripts so that it gives me a new desktop background when I resume, since I've been having so much fun with my random wallpaper script.

Later update: Alas, I was too optimistic. Turns out it actually only works about one time out of three. The other two times, it hangs after X comes up, or else it initially reboots instead of resuming. Bummer!

Tags: linux, laptop, suspend, ubuntu
[ 11:07 Apr 12, 2007    More linux | permalink to this entry | ]

Ubuntu "Breezy Badger"

I installed the latest Ubuntu Linux, called "Breezy Badger", just before leaving to visit family over the holidays. My previous Ubuntu attempt on this machine had been rather unstable (probably not Ubuntu's fault -- 2.6 kernels and this laptop don't get along very well) but Ubuntu seems to have some very sharp kernel developers, so I was curious to see whether there'd been progress.

Installation: Didn't go well. I had most of the same problems I'd had installing Hoary to this laptop (mostly due to the installer assuming that a CDROM and network must remain connected throughout the install, something that's impossible on a laptop where both of those functions require sharing the single PCMCIA port). The Breezy installer has the additional "feature" that it tends to hang if you change things like the CDROM while the install is in progress, trashing everything and forcing you to restart from the beginning. (Filed bug 20443.)

Networking: But eventually I found a sequence that let me get a network-less Breezy onto the laptop, and I'm happy to report that Breezy's built-in networking tools were able to add networking after the first boot (something that hadn't worked in Hoary). Well, admittedly I did have to add a script, /etc/hotplug/pci/3c59x, to call ifup when my cardbus network card is plugged in; but every other distro needs that too, and Breezy is the first 2.6-based distro which correctly calls the script every time.

Suspend: Once up and running, Breezy shows impressive laptop savvy. Like Hoary, it can suspend either to disk or to RAM; unlike Hoary, it can do this without my needing to hack any config files except to uncomment the line enabling suspend to RAM in /etc/default/acpi-support. It does print various error messages on stdout when it resumes from sleep or hibernate, but that's a minor issue.

Not only that, but it restores both network and usb when resuming from suspend (on hoary I had to hack some of the suspend scripts to make that work).

(Kernel flakiness: Well, mostly it suspends fine. Unplugging a usb mouse at the wrong time still causes a kernel hang. That's a 2.6 bug, not an Ubuntu-specific problem. And the system also tends to hang and need to be power cycled about one time out of five when exiting X; perhaps it's an Xorg bug.)

Ironically, my "safe" partition on this laptop (a much- modified Debian sarge) mysteriously stopped seeing PCMCIA on the first day away from home, so I ended up using Breezy for the whole trip and giving it a good workout.

Hal: One problem Breezy shares with Hoary is that every few seconds, the hald daemon makes the hard drive beep and whir. Unlike Hoary, which had an easy solution, Breezy ignores the storage_media_check_enabled and storage_automount_enabled hints. The only way I found to disable the beeping was to kill hald entirely by renaming /usr/sbin/hald (it's not called from /etc/init.d, and I never did find out who was starting it so I could disable it). Removing hald seems to have caused no ill effects; at least, hotplug of pcmcia and usb still works, as do udev rules. (Filed bug 21238.

Udev: Oh, about those udev rules! Regular readers may recall that I had some trouble with Hoary regarding udev choking on multiple flash card readers which I solved on my desktop machine with a udev rule that renames the four fixed, always present devices. But with a laptop, I don't have fixed devices; I wanted a setup that would work regardless of what I plugged in. That required a new udev rule. Here's the rule that worked for me: in /etc/udev/permissions.rules, change

BUS=="scsi", KERNEL=="sd[a-z]*", PROGRAM="/etc/udev/scripts/removable.sh %k 'usb ieee1394'", RESULT="1", MODE="0640", GROUP="plugdev"

to

BUS=="scsi", KERNEL=="sd[a-z]*", NAME{all_partitions}="%k", MODE="0640", GROUP="plugdev"

Note that this means that whatever scripts/removable.sh does, it's not happening any more. That doesn't seem to have caused any problem, though. (Filed bug 21662 on that problem.)

Conclusion: Overall, Breezy is quite impressive and required very little tweaking before it was usable. It was my primary distro for two weeks while travelling; I may switch to it on the desktop once I find a workaround for bug 352358 in GTK 2.8 (which has been fixed in gnome cvs, but that doesn't make it any less maddening when using the buggy version).

Tags: linux, ubuntu, laptop
[ 22:43 Jan 04, 2006    More linux | permalink to this entry | ]

Ubuntu "Hoary Hedgehog" on a Vaio SR17 Laptop

I've been experimenting with Ubuntu's second release, "Hoary Hedgehog" off and on since just before it was released.

Overall, I'm very impressed. It's quite usable on a desktop machine; but more important, I'm blown away by the fact that Ubuntu's kernel team has made a 2.6 acpi kernel that actually works on my aging but still beloved little Vaio SR17 laptop. It can suspend to RAM (if I uncomment ACPI_SLEEP in /etc/defaults/acpi-support), it can suspend to disk, it gets power button events (which are easily customizable: by default it shuts the machine down, but if I replace powerbtn.sh with a single line calling sleep.sh, it suspends), it can read the CPU temperature. Very cool.

One thing didn't work: USB stopped working when resuming after a suspend to RAM. It turned out this was a hotplug problem, not a kernel problem: the solution was to add calls to /etc/init.d/hotplug stop and /etc/init.d/hotplug start in the /etc/acpi/sleep.sh script. Problem solved (except now resuming takes forever, as does booting; I need to tune that hotplug startup script and get rid of whatever is taking so long).

Sonypi (the jogdial driver) also works. It isn't automatically loaded (I've added it to /etc/modules), and it disables the power button (so much for changing the script to call sleep.sh), a minor annoyance. But when loaded, it automatically creates /dev/sonypi, so I don't have to play the usual guessing game about which minor number it wanted this time.

Oh, did I mention that the Hoary live CD also works on the Vaio? It's the first live linux CD which has ever worked on this machine (all the others, including rescue disks like the Bootable Business Card and SuperRescue, have problems with the Sony PCMCIA-emulating-IDE CD drive). It's too slow to use for real work, but the fact that it works at all is amazing.

I have to balance this by saying that Ubuntu's not perfect. The installer, which is apparently the Debian Sarge installer dumbed down to reduce the number of choices, is inconsistent, difficult, and can't deal with a networkless install (which, on a laptop which can't have a CD drive and networking at the same time because they both use the single PCMCIA slot, makes installation quite tricky). The only way I found was to boot into expert mode, skip the network installation step, then, after the system was up and running (and I'd several times dismissed irritating warnings about how it couldn't find the network, therefore "some things" in gnome wouldn't work properly, and did I want to log in anyway?) I manually edited /etc/network/interfaces to configure my card (none of Ubuntu's built-in hardware or network configuration tools would let me configure my vanilla 3Com card; presumably they depend on something that would have been done at install time if I'd been allowed to configure networking then). (Bug 2835.)

About that expert mode: I needed that even for the desktop, because hoary's normal installer doesn't offer an option for a static IP address. But on both desktop and laptop this causes a problem. You see, hoary's normal mode of operation is to add the first-created user to the sudoers list, and then not create a root account at all. All of their system administration tools depend on the user being in the sudoers file. Fine. But someone at ubuntu apparently decided that anyone installing in expert mode probably wants a root account (no argument so far) and therefore doesn't need to be in the sudoers file. Which means that after the install, none of the admin tools work; they just pop up variants on a permission denied dialog. The solution is to use visudo to add yourself to /etc/sudoers. (Bugs 7636 and 9832.)

Expert mode also has some other bugs, like prompting over and over for additional kernel modules (bug 5999).

Okay, so nothing's perfect. I'm not very impressed with Hoary's installer, though most of its problems are inherited from Sarge. But once it's on the machine, Hoary works great. It's a modern Debian-based Linux that gets security upgrades (something Debian hasn't been able to do, though they keep making noises about finally releasing Sarge). And there's that amazing kernel. Now that I have the hotplug-on-resume problem fixed, I'm going to try using it as the primary OS on the laptop for a while, and see how it goes.

Tags: linux, ubuntu, laptop, vaio
[ 17:29 Jun 03, 2005    More linux | permalink to this entry | ]

Good article on laptop Linux

Linux Magazine has a good article by Jonathan A. Zdziarski on Linux on the laptop: Ten power tools for the mobile Linux user. He gives hints such as what services to turn off for better power management, and how to configure apmd to turn off those services automatically; finding modules to drive various types of wireless internet cards; various ways of minimizing disk activity; and even making data calls with a mobile phone.

Lots of good information in there!

Tags: linux, laptop
[ 20:51 Oct 07, 2004    More linux/laptop | permalink to this entry | ]

swsusp working, sort of

I got swsusp working on blackbird. Re-reading the kernel documentation with a night's sleep behind me revealed that at the very end of swsusp.txt, there's code for a C program to suspend non-ACPI machines. Worked fine! swsusp in 2.6.7 doesn't quite resume X properly (I had to ctrl-alt-FN back and forth a few times before I saw my X screen) but it's progress, anyway.

Tags: linux, suspend, laptop
[ 21:00 Jun 27, 2004    More linux | permalink to this entry | ]

PenLUG: Linux on Laptops

Great talk at PenLUG by Chander Kant of Linux Certified, on Linux on Laptops. It was much the same talk he gave a month ago at SVLUG, except at PenLUG he got to give his talk without being pestered by a bunch of irritating flamers, and it was possible for people to ask real questions and get answers.

The biggest revelation: "Suspend to Disk" in the 2.6 kernel is actually ACPI S4 suspend, and won't do anything on a machine that doesn't support ACPI S4. Why can't they say that in the help? Sheesh!

Tags: linux, laptop
[ 00:00 Jun 25, 2004    More linux | permalink to this entry | ]