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authorTakashi Iwai <tiwai@suse.de>2021-05-16 18:17:55 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-05-26 12:05:16 +0200
commit048840df6de8bd40deb55a28f340949cb882340d (patch)
treed65268cf308a6a728e5da8a9607f39c6edb78457 /sound/pci
parenta67a88f9e667fb63b936b05083e6d8799022a63c (diff)
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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.c7
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;
}