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authorTakashi Iwai <tiwai@suse.de>2021-05-16 18:17:55 +0200
committerTakashi Iwai <tiwai@suse.de>2021-05-16 18:17:55 +0200
commitc1f0616124c455c5c762b6f123e40bba5df759e6 (patch)
tree77f671b4cfc9b6b40b324b0fd3a5e018c202065f /sound
parent1d5cfca286178ce81fb0c8a5f5777ef123cd69e4 (diff)
ALSA: intel8x0: Don't update period unless prepared
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>
Diffstat (limited to 'sound')
-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 35903d1a1cbd..5b124c4ad572 100644
--- a/sound/pci/intel8x0.c
+++ b/sound/pci/intel8x0.c
@@ -331,6 +331,7 @@ 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;
};
@@ -691,6 +692,9 @@ 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);
@@ -881,6 +885,7 @@ 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),
@@ -902,6 +907,7 @@ 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 0;
}
@@ -976,6 +982,7 @@ 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;
}

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