-----Original Message----- From: Eoff, Ullysses A Sent: Tuesday, July 28, 2015 1:38 PM To: Yang, Libin; tiwai@suse.de; alsa-devel@alsa-project.org Cc: Lee, Zhuo-hao Subject: RE: [PATCH v2] ALSA: hda - Fix race condition between HDA driver and runtime PM
-----Original Message----- From: Yang, Libin Sent: Monday, July 27, 2015 10:30 PM To: Eoff, Ullysses A; tiwai@suse.de; alsa-devel@alsa-project.org Cc: Lee, Zhuo-hao Subject: RE: [PATCH v2] ALSA: hda - Fix race condition between HDA
driver and runtime PM
Hi Ullysses,
-----Original Message----- From: Eoff, Ullysses A Sent: Tuesday, July 28, 2015 1:27 PM To: Yang, Libin; tiwai@suse.de; alsa-devel@alsa-project.org Cc: Lee, Zhuo-hao Subject: RE: [PATCH v2] ALSA: hda - Fix race condition between
HDA
driver and runtime PM
-----Original Message----- From: Yang, Libin Sent: Monday, July 27, 2015 10:20 PM To: Eoff, Ullysses A; tiwai@suse.de; alsa-devel@alsa-project.org Cc: Lee, Zhuo-hao Subject: RE: [PATCH v2] ALSA: hda - Fix race condition between
HDA
driver and runtime PM
Hi Ullysses,
-----Original Message----- From: Eoff, Ullysses A Sent: Tuesday, July 28, 2015 12:20 PM To: tiwai@suse.de; alsa-devel@alsa-project.org Cc: Lee, Zhuo-hao; Yang, Libin; Eoff, Ullysses A Subject: [PATCH v2] ALSA: hda - Fix race condition between
HDA
driver
and runtime PM
Don't execute runtime suspend if HDA is not finished initializing. Otherwise, the following errors can occur in hda:
snd_hda_intel 0000:00:1b.0: CORB reset timeout#2, CORBRP =
65535
snd_hda_intel 0000:00:1b.0: no codecs initialized
Debugged and root-cause found by zhuo-hao.lee@intel.com
v2: remove unnecessary extra check for chip init (libin)
Signed-off-by: U. Artie Eoff ullysses.a.eoff@intel.com
sound/pci/hda/hda_intel.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c
b/sound/pci/hda/hda_intel.c
index b729b25a6ad6..15d4e28fc64e 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1017,17 +1017,19 @@ static int azx_runtime_idle(struct
device
*dev) struct snd_card *card = dev_get_drvdata(dev); struct azx *chip; struct hda_intel *hda;
struct hdac_bus *bus;
if (!card) return 0;
chip = card->private_data; hda = container_of(chip, struct hda_intel, chip);
bus = azx_bus(chip); if (chip->disabled || hda->init_failed || !chip->running)
I mean we don't need '!chip->running' either. Otherwise, initialization may be interrupted.
!chip->running condition comes from patch 1/2 and is needed to avoid race with async probe. Are you saying we don't need patch 1/2?
Do you mean removing patch 1/2 will cause race?
Yes. PM ops could trigger before azx_probe_continue finishes which results in a NULL deref kernel crash.
If so, agree with Takashi's comment's on the first patch, we can return -EBUSY for this case.
return 0;if (!power_save_controller
|| !azx_has_pm_runtime(chip) ||
azx_bus(chip)->codec_powered)
bus->codec_powered || !bus->chip_init)return -EBUSY;
return 0;
-- 1.9.3