At Wed, 20 Nov 2013 13:05:23 +0100, Takashi Iwai wrote:
At Wed, 20 Nov 2013 09:54:42 +0100, David Henningsson wrote:
(Adding Mengdong to cc)
On 11/19/2013 05:51 PM, Takashi Iwai wrote:
We got bug reports of the stalled HD-audio, typically after S3 or S4, and it turned out that they seemed triggered by runtime PM on Lynx Point and Lynx Point-LP controllers. As there is no way to recover properly from the stalled controller, it's safer to disable the runtime PM support on these chips for now.
Oh, this is a bit sad news. Have you talked to Intel about it?
Anyway, I saw something similar a while ago, but never with access to the hardware, and then it was difficult to reproduce for the person on the other side. Nevertheless, when I read through the PM code I found that the GCTL register was sometimes accessed with readb (although it is a 32 bit register), so I wrote a patch for that, but the testing results of this patch were a bit inconclusive, so I never upstreamed it.
Anyway, I'm attaching the draft patch. Do you think it could be related?
It didn't change the behavior although the change looks good.
After a long debugging session in this morning, I finally nailed down. This was the fault in the sound driver after all, shamefully :)
The fix patch is below.
The code needs a bit clean up, and I have it, but will apply this for 3.14.
Takashi
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From: Takashi Iwai tiwai@suse.de Subject: [PATCH 1/2] ALSA: hda - Fix unbalanced runtime PM notification at resume
BTW, it's marked as 1/2 just because of the clean up patch I mentioned above. Only this one is needed for now.
Takashi