On Tue, 28 Jul 2015 08:05:08 +0200, Yang, Libin wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Tuesday, July 28, 2015 1:39 PM To: Eoff, Ullysses A Cc: alsa-devel@alsa-project.org; Lee, Zhuo-hao; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - skip runtime PM if async probe is not finished
On Mon, 27 Jul 2015 23:34:53 +0200, U. Artie Eoff wrote:
Crash can occur if runtime PM is triggered before the async probe finishes via the azx_firmware_cb when
CONFIG_SND_HDA_PATCH_LOADER
is defined.
Don't execute PM ops if the async probe has not completed yet.
The probe is finished when chip->running is true.
Signed-off-by: U. Artie Eoff ullysses.a.eoff@intel.com
sound/pci/hda/hda_intel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 735bdcb04ce8..b729b25a6ad6 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1023,7 +1023,7 @@ static int azx_runtime_idle(struct device
*dev)
chip = card->private_data; hda = container_of(chip, struct hda_intel, chip);
- if (chip->disabled || hda->init_failed)
- if (chip->disabled || hda->init_failed || !chip->running) return 0;
For !chip->running, it's better to return -EBUSY.
The disabled and init_failed flags are checked in runtime_suspend() and runtime_resume() to skip the whole procedures, too.
And I guess the check of chip->running should suffice even without the second patch. It assures that the bus is powered on.
As, in runtime_resume will call azx_init_chip(), which may sleep, is there any race when calling azx_runtime_resume(), azx_runtime_idle is called and enter azx_runtime_suspend()? Or the ACPI subsystem will handle such situation?
The reentrace is avoided in the runtime PM core side, IIRC.
Takashi