On Mon, Feb 16, 2015 at 08:40:47AM -0800, Andrew Lutomirski wrote: > On Mon, Feb 16, 2015 at 7:35 AM, Xavier Naveira <xnaveira@xxxxxxxxx> wrote: > > On Mon, Feb 16, 2015 at 07:24:43AM -0800, Andrew Lutomirski wrote: > >> On Feb 16, 2015 3:59 AM, "Xavier Naveira" <xnaveira@xxxxxxxxx> wrote: > >> > > >> > Hi, > >> > > >> > Since the kernel 3.19 mute button stopped working for me, this seems to > >> > be the commit: > >> > > >> > > >> http://git.infradead.org/users/dvhart/linux-platform-drivers-x86.git/commitdiff/9a417ec0c9d1f7af5394333411fc4d98adb8761b > >> > > >> > Before that (3.18.7) the button worked as well as its led although the > >> > state was reset to "unmuted" after suspend. > >> > > >> > I'm on a Lenovo thinkpad x240 running ubuntu 14.10 with kernel compiled > >> > from kernel.org. > >> > > >> > I'll be glad to help debugging the problem. > >> > >> What desktop environment are you using? I suspect that you are > >> misconfigured a bit, since I've had reports that this works on the X240. I > >> really ought to write a blog post about it. > >> > >> --Andy > >> > >> > > >> > > >> > Xavier > > > > Hi Andy, > > > > My desktop environent is i3 on top of a default installation of xubuntu. > > The kernel is the only thing that changes and I can reproduce the > > problem every time. > > Here's the basics of what's going on: > > Prior to 3.19, the ThinkPad embedded controller would automatically > mute a ThinkPad-specific hardware switch and light an LED when you > pressed the mute button. The kernel had partial support for this: on > more recent kernels, it would try to keep the LED in sync with the > *standard* (non-ThinkPad-specific) mute controls, and it exposed a > rather buggy separate ALSA mixer that could directly poke the ThinkPad > hardware control. The upshot was that, depending on what your > userspace software was doing, the mute button would sometimes do > something vaguely like what you expected, and it would sometimes > behave erratically. > > Starting with 3.19, the default behavior is to ask the embedded > controller to disable all the magic. The kernel will keep the mute > LED in sync with the software control, the hardware switch is disabled > entirely, and the mute button is just a button. In other words, a > ThinkPad on 3.19 or newer will work just like any other laptop, except > with a bonus mute LED. > > If you were relying on the old behavior, your mute button might no > longer have any apparent effect. Users of more full-featured desktop > environments (GNOME and KDE, I think) seem to be fine by default. > Otherwise, you might need to set up your desktop environment the same > way you would for a non-ThinkPad laptop. To get you started, try > these commands from a shell: > > To toggle the mute state: > $ amixer -q set Master toggle > > To toggle the mic mute state: > $ amixer -q set Capture toggle > > If these work, then you should be able to bind them to the appropriate > key presses using a desktop-specific configuration along the lines of: > > bindsym XF86AudioMute exec amixer -q set Master toggle > > As an alternative, you can get the old behavior back by setting > thinkpad_acpi.software_mute=0, but then you'll have the same problem > again if you ever migrate to a non-ThinkPad laptop or if Lenovo ever > decides to save a few cents on new models by getting rid of the extra > hardware mute control. Hi Andy, Thank you for a thorough explanation! Ok I see, so instead of trying to support every hardware configuration in Thinkpads you treat the mute button as just another key of the keyboard and let the software deal with it. It is a shame that manufacturers can't keep standards (de facto or actual) on top of not delivering proper Linux modules. My interest on how Linux kernel and drivers has grown lately and I figured that a good way of learning is trying to understand (and if possible improve) the thinkpad_acpi module. I was actually trying to make the mute button restore its old state after suspend but now I guess I've to look for another task :) There is plenty, the rfkill button isn't killing bluetooth or gsm but only wifi for example (that could even not be a problem with thinkpad_acpi though). Anyway, amixer command doesn't seem to work in my setup so I guess I'll spend some time digging a software solution to make the mute button work for me again. Thank you for your work and for the explanation. X > > --Andy > > > > > X ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! 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