ALSA: hda - Serialize codec registrations

In the current code, the codec registration may happen both at the
codec bind time and the end of the controller probe time.  In a rare
occasion, they race with each other, leading to Oops due to the still
uninitialized card device.

This patch introduces a simple flag to prevent the codec registration
at the codec bind time as long as the controller probe is going on.
The controller probe invokes snd_card_register() that does the whole
registration task, and we don't need to register each piece
beforehand.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2019-01-30 17:46:03 +01:00
parent 35a39f9856
commit 305a0ade18
3 changed files with 5 additions and 1 deletions

View File

@ -68,6 +68,7 @@ struct hda_bus {
unsigned int response_reset:1; /* controller was reset */
unsigned int in_reset:1; /* during reset operation */
unsigned int no_response_fallback:1; /* don't fallback at RIRB error */
unsigned int bus_probing :1; /* during probing process */
int primary_dig_out_type; /* primary digital out PCM type */
unsigned int mixer_assigned; /* codec addr for mixer name */

View File

@ -115,7 +115,8 @@ static int hda_codec_driver_probe(struct device *dev)
err = snd_hda_codec_build_controls(codec);
if (err < 0)
goto error_module;
if (codec->card->registered) {
/* only register after the bus probe finished; otherwise it's racy */
if (!codec->bus->bus_probing && codec->card->registered) {
err = snd_card_register(codec->card);
if (err < 0)
goto error_module;

View File

@ -2185,6 +2185,7 @@ static int azx_probe_continue(struct azx *chip)
int dev = chip->dev_index;
int err;
to_hda_bus(bus)->bus_probing = 1;
hda->probe_continued = 1;
/* bind with i915 if needed */
@ -2269,6 +2270,7 @@ out_free:
if (err < 0)
hda->init_failed = 1;
complete_all(&hda->probe_wait);
to_hda_bus(bus)->bus_probing = 0;
return err;
}