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| author | Muli Ben-Yehuda <muli@il.ibm.com> | 2007-07-17 04:05:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-17 10:23:10 -0700 |
| commit | 3b20b9b4e985fcc48b4eea401cb289a856422c93 (patch) | |
| tree | 7af15a26530ae4c1623cd02a4722678747741a28 /sound/oss | |
| parent | d8f75b9183d613d3c29ea451a1cfb793daad5034 (diff) | |
| download | lwn-3b20b9b4e985fcc48b4eea401cb289a856422c93.tar.gz lwn-3b20b9b4e985fcc48b4eea401cb289a856422c93.zip | |
OSS trident: fix locking around write_voice_regs
trident_write_voice_regs() was getting called with the card spinlock held in
only some cases. Fix it.
Explanation: we allocate a new virtual channel in open, and then we frob some
hardware registers (in write_voice_regs) for that channel. But the hardware
registers are shared with other channels, which may be trying to frob the some
registers (albeit for another channel) via ioctl(SNDCTL_DSP_SPEED).
Fixed bugzilla.kernel.org bug #8172 (http://bugme.osdl.org/show_bug.cgi?id=8172)
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: <tammy000@gmail.com>
Cc: <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'sound/oss')
| -rw-r--r-- | sound/oss/trident.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/sound/oss/trident.c b/sound/oss/trident.c index 3e408f491927..2e3e78e1bf67 100644 --- a/sound/oss/trident.c +++ b/sound/oss/trident.c @@ -2702,6 +2702,7 @@ trident_open(struct inode *inode, struct file *file) struct trident_card *card = devs; struct trident_state *state = NULL; struct dmabuf *dmabuf = NULL; + unsigned long flags; /* Added by Matt Wu 01-05-2001 */ /* TODO: there's some redundacy here wrt the check below */ @@ -2779,7 +2780,9 @@ trident_open(struct inode *inode, struct file *file) /* set default channel attribute to normal playback */ dmabuf->channel->attribute = CHANNEL_PB; } + spin_lock_irqsave(&card->lock, flags); trident_set_dac_rate(state, 8000); + spin_unlock_irqrestore(&card->lock, flags); } if (file->f_mode & FMODE_READ) { @@ -2797,7 +2800,9 @@ trident_open(struct inode *inode, struct file *file) dmabuf->channel->attribute = (CHANNEL_REC | PCM_LR | MONO_MIX); } + spin_lock_irqsave(&card->lock, flags); trident_set_adc_rate(state, 8000); + spin_unlock_irqrestore(&card->lock, flags); /* Added by Matt Wu 01-05-2001 */ if (card->pci_id == PCI_DEVICE_ID_ALI_5451) |