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@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
include/sound/hda_codec.h | 1 +
sound/pci/hda/hda_bind.c | 3 ++-
sound/pci/hda/hda_intel.c | 2 ++
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/sound/hda_codec.h b/include/sound/hda_codec.h
index 7fa48b100936..cc7c8d42d4fd 100644
--- a/include/sound/hda_codec.h
+++ b/include/sound/hda_codec.h
@@ -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 */
diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c
index 9174f1b3a987..1ec706ced75c 100644
--- a/sound/pci/hda/hda_bind.c
+++ b/sound/pci/hda/hda_bind.c
@@ -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;
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index e784130ea4e0..e5c49003e75f 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -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 @@ static int azx_probe_continue(struct azx *chip)
if (err < 0)
hda->init_failed = 1;
complete_all(&hda->probe_wait);
+ to_hda_bus(bus)->bus_probing = 0;
return err;
}
--
2.16.4
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