On Mon, Mar 16, 2015 at 7:29 AM, Mario Limonciello <mario_limonciello@xxxxxxxx> wrote: > > On 03/14/2015 02:17 PM, Benjamin Tissoires wrote: >> >> [top posting, sorry] >> >> Jason made some interesting progress today: >> with the patch in https://lkml.org/lkml/2015/3/12/149, the sound card >> is not switched in the I2S mode and works while the touchpad keeps >> using I2C. >> It looks like suspend/resume is also fixed by that :) >> >> I thought it was worth mentioning to the people in this thread. >> >> Cheers, >> Benjamin > > Benjamin, > > Thanks for reporting the progress to me. > > Jason, > > Are you sure upon the particulars of what's happening here? That patch only > modifies the behavior of how the EC is configured. > I'm not aware of any suspend/resume issues, especially related to the EC, so > that really surprises me. My initial suspicion is a suspend/resume issue > you encountered was rare enough that you just haven't hit it yet even with > that patch applied. Maybe something in the out of kernel Broadcom wireless > driver if you are still using the Broadcom card with it. It's nothing about the wireless. I swapped it out for an intel card on day 3 or so. Yes, I am almost 100% sure that this affects suspend/resume. Prior to the _REV hack, my laptop *never* suspended correctly. Now it regularly suspends just fine. I also double-checked that rebasing on Linus' master didn't affect it. With the _REV hack it doesn't suspend. Without it, it's just fine. I don't know much about suspend/resume but is it possible that the problem is the kernel not being able to properly shut down the sound card? > I believe you are incorrect in the audio being put in HDA mode. It's more > likely that it's operating closer to properly in I2S mode. Here's some > background around what that patch is doing. > When this platform started development the Linux kernel didn't yet respond > true to Windows 2013. All our validation for Linux happened on kernel 3.13. That matches what I've seen. With the _REV hack, I see nothing about HDA in dmesg and I get different audio messages than with an _OSI of Windows 2009. > _OSI of Windows 2009 is supposed to set it for PS2 mouse, HDA device in ACPI > and configure the EC to set up the Realtek codec for HDA mode. Linux was > planned to mirror this behavior during development. > _OSI of Windows 2013 is supposed to set it up for I2C mouse, I2S audio in > ACPI and configure the EC to set up the Realtek codec for I2S mode. > > From when the platform was in development a _REV check was put in for > Windows 2013 to make sure that in case the kernel started to respond to > Windows 2013 we would still have it running in the intended modes for Linux. > There was a mistake in this _REV check though that caused the I2S ACPI > device but to misconfigure the EC. The reason _REV = 2 and _OSI = Windows > 2013 you are getting working audio is the rt286 driver is starting to be > used. You can validate this by looking at dmesg for lines about rt286. > Realtek recently submitted some patches for this at Dell's request. There > are still a variety of issues with the I2S driver including jack detection > and some other microphone issues. Pulseaudio will possibly need some > patches to work properly with this device too. Ideally we don't want > customers to use I2S mode on Linux until it's solid. > > I don't believe this was in Linus' tree yet, so if you don't have it you can > apply it and it should fix at least one microphone issue when in I2S mode. > http://mailman.alsa-project.org/pipermail/alsa-devel/2015-March/088724.html > > Whether or not that _REV patch gets applied to the kernel we are fixing this > incorrect behavior for Windows 2013 _OSI and Linux in upcoming BIOS A02. > In BIOS A02 there will still be a _REV check but it will do this: > Windows 2013 _OSI, _REV 5: I2C mouse, HDA device in ACPI, configure EC for > HDA mode. > Windows 2013 _OSI, _REV 2: I2C mouse, I2S device in ACPI, configure EC for > I2S mode. I look forward to seeing the update. Thanks for working on this! --Jason Ekstrand -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
