diff options
| author | Takashi Iwai <tiwai@suse.de> | 2021-05-16 18:17:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-26 12:05:16 +0200 |
| commit | 048840df6de8bd40deb55a28f340949cb882340d (patch) | |
| tree | d65268cf308a6a728e5da8a9607f39c6edb78457 /sound/pci | |
| parent | a67a88f9e667fb63b936b05083e6d8799022a63c (diff) | |
ALSA: intel8x0: Don't update period unless prepared
commit c1f0616124c455c5c762b6f123e40bba5df759e6 upstream.
The interrupt handler of intel8x0 calls snd_intel8x0_update() whenever
the hardware sets the corresponding status bit for each stream. This
works fine for most cases as long as the hardware behaves properly.
But when the hardware gives a wrong bit set, this leads to a zero-
division Oops, and reportedly, this seems what happened on a VM.
For fixing the crash, this patch adds a internal flag indicating that
the stream is ready to be updated, and check it (as well as the flag
being in suspended) to ignore such spurious update.
Cc: <stable@vger.kernel.org>
Reported-and-tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Link: https://lore.kernel.org/r/s5h5yzi7uh0.wl-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound/pci')
| -rw-r--r-- | sound/pci/intel8x0.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c index 6ff94d8ad86e..2a73fc4fd019 100644 --- a/sound/pci/intel8x0.c +++ b/sound/pci/intel8x0.c @@ -354,6 +354,7 @@ struct ichdev { unsigned int ali_slot; /* ALI DMA slot */ struct ac97_pcm *pcm; int pcm_open_flag; + unsigned int prepared:1; unsigned int suspended: 1; }; @@ -714,6 +715,9 @@ static inline void snd_intel8x0_update(struct intel8x0 *chip, struct ichdev *ich int status, civ, i, step; int ack = 0; + if (!ichdev->prepared || ichdev->suspended) + return; + spin_lock_irqsave(&chip->reg_lock, flags); status = igetbyte(chip, port + ichdev->roff_sr); civ = igetbyte(chip, port + ICH_REG_OFF_CIV); @@ -907,6 +911,7 @@ static int snd_intel8x0_hw_params(struct snd_pcm_substream *substream, if (ichdev->pcm_open_flag) { snd_ac97_pcm_close(ichdev->pcm); ichdev->pcm_open_flag = 0; + ichdev->prepared = 0; } err = snd_ac97_pcm_open(ichdev->pcm, params_rate(hw_params), params_channels(hw_params), @@ -928,6 +933,7 @@ static int snd_intel8x0_hw_free(struct snd_pcm_substream *substream) if (ichdev->pcm_open_flag) { snd_ac97_pcm_close(ichdev->pcm); ichdev->pcm_open_flag = 0; + ichdev->prepared = 0; } return snd_pcm_lib_free_pages(substream); } @@ -1002,6 +1008,7 @@ static int snd_intel8x0_pcm_prepare(struct snd_pcm_substream *substream) ichdev->pos_shift = (runtime->sample_bits > 16) ? 2 : 1; } snd_intel8x0_setup_periods(chip, ichdev); + ichdev->prepared = 1; return 0; } |