4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Takashi Iwai tiwai@suse.de
commit 305a0ade180981686eec1f92aa6252a7c6ebb1cf upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/pci/hda/hda_bind.c | 3 ++- sound/pci/hda/hda_codec.h | 1 + sound/pci/hda/hda_intel.c | 2 ++ 3 files changed, 5 insertions(+), 1 deletion(-)
--- a/sound/pci/hda/hda_bind.c +++ b/sound/pci/hda/hda_bind.c @@ -109,7 +109,8 @@ static int hda_codec_driver_probe(struct 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; --- a/sound/pci/hda/hda_codec.h +++ b/sound/pci/hda/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 */ --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -2100,6 +2100,7 @@ static int azx_probe_continue(struct azx int val; int err;
+ to_hda_bus(bus)->bus_probing = 1; hda->probe_continued = 1;
/* Request display power well for the HDA controller or codec. For @@ -2200,6 +2201,7 @@ i915_power_fail: if (err < 0) hda->init_failed = 1; complete_all(&hda->probe_wait); + to_hda_bus(bus)->bus_probing = 0; return err; }