-----Original Message----- From: alsa-devel-bounces@alsa-project.org [mailto:alsa-devel-bounces@alsa-project.org] On Behalf Of Takashi Iwai Sent: Monday, July 27, 2015 10:39 PM To: Eoff, Ullysses A Cc: Yang, Libin; alsa-devel@alsa-project.org; Lee, Zhuo-hao Subject: Re: [alsa-devel] [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.
Hmm... wait a second. I think we still need to check bus->chip_init as in the second patch. I just noticed that the async probe finishes (i.e. chip->running = 1) before chip init executes (i.e. before bus->chip_init is set). This allows a small window for the issue I described in my second patch to occur.
I already sent another patch to replace these two... but I didn't add the check for bus->chip_init in that patch. I'll create a v2 for that but will wait for your feedback first.
thanks,
Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel