Commit 3b20b9b4 authored by Muli Ben-Yehuda's avatar Muli Ben-Yehuda Committed by Linus Torvalds

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: default avatarMuli Ben-Yehuda <muli@il.ibm.com>
Cc: <tammy000@gmail.com>
Cc: <bunk@stusta.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d8f75b91
...@@ -2702,6 +2702,7 @@ trident_open(struct inode *inode, struct file *file) ...@@ -2702,6 +2702,7 @@ trident_open(struct inode *inode, struct file *file)
struct trident_card *card = devs; struct trident_card *card = devs;
struct trident_state *state = NULL; struct trident_state *state = NULL;
struct dmabuf *dmabuf = NULL; struct dmabuf *dmabuf = NULL;
unsigned long flags;
/* Added by Matt Wu 01-05-2001 */ /* Added by Matt Wu 01-05-2001 */
/* TODO: there's some redundacy here wrt the check below */ /* TODO: there's some redundacy here wrt the check below */
...@@ -2779,7 +2780,9 @@ trident_open(struct inode *inode, struct file *file) ...@@ -2779,7 +2780,9 @@ trident_open(struct inode *inode, struct file *file)
/* set default channel attribute to normal playback */ /* set default channel attribute to normal playback */
dmabuf->channel->attribute = CHANNEL_PB; dmabuf->channel->attribute = CHANNEL_PB;
} }
spin_lock_irqsave(&card->lock, flags);
trident_set_dac_rate(state, 8000); trident_set_dac_rate(state, 8000);
spin_unlock_irqrestore(&card->lock, flags);
} }
if (file->f_mode & FMODE_READ) { if (file->f_mode & FMODE_READ) {
...@@ -2797,7 +2800,9 @@ trident_open(struct inode *inode, struct file *file) ...@@ -2797,7 +2800,9 @@ trident_open(struct inode *inode, struct file *file)
dmabuf->channel->attribute = (CHANNEL_REC | PCM_LR | dmabuf->channel->attribute = (CHANNEL_REC | PCM_LR |
MONO_MIX); MONO_MIX);
} }
spin_lock_irqsave(&card->lock, flags);
trident_set_adc_rate(state, 8000); trident_set_adc_rate(state, 8000);
spin_unlock_irqrestore(&card->lock, flags);
/* Added by Matt Wu 01-05-2001 */ /* Added by Matt Wu 01-05-2001 */
if (card->pci_id == PCI_DEVICE_ID_ALI_5451) if (card->pci_id == PCI_DEVICE_ID_ALI_5451)
......
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