diff options
author | Richard Zidlicky <rz@linux-m68k.org> | 2010-08-24 08:52:36 -0400 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2010-09-27 21:21:59 -0400 |
commit | 3cdadc50bbe8f04c1231c8af614cafd7ddd622bf (patch) | |
tree | f42de4ed576985173c30d19befbe5570a6798948 | |
parent | 970d14c6cca8c71307a4d23fe373c5895175b2d7 (diff) |
V4L/DVB: dvb: fix smscore_getbuffer() logic
Drivers shouldn't sleep while holding a spinlock. A previous workaround
were to release the spinlock before callinc schedule().
This patch uses a different approach: it just waits for the
siano hardware to answer.
Signed-off-by: Richard Zidlicky <rz@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r-- | drivers/media/dvb/siano/smscoreapi.c | 31 |
1 files changed, 12 insertions, 19 deletions
diff --git a/drivers/media/dvb/siano/smscoreapi.c b/drivers/media/dvb/siano/smscoreapi.c index d93468cd3a85..ff3b0fa901b3 100644 --- a/drivers/media/dvb/siano/smscoreapi.c +++ b/drivers/media/dvb/siano/smscoreapi.c | |||
@@ -1098,33 +1098,26 @@ EXPORT_SYMBOL_GPL(smscore_onresponse); | |||
1098 | * | 1098 | * |
1099 | * @return pointer to descriptor on success, NULL on error. | 1099 | * @return pointer to descriptor on success, NULL on error. |
1100 | */ | 1100 | */ |
1101 | struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) | 1101 | |
1102 | struct smscore_buffer_t *get_entry(struct smscore_device_t *coredev) | ||
1102 | { | 1103 | { |
1103 | struct smscore_buffer_t *cb = NULL; | 1104 | struct smscore_buffer_t *cb = NULL; |
1104 | unsigned long flags; | 1105 | unsigned long flags; |
1105 | 1106 | ||
1106 | DEFINE_WAIT(wait); | ||
1107 | |||
1108 | spin_lock_irqsave(&coredev->bufferslock, flags); | 1107 | spin_lock_irqsave(&coredev->bufferslock, flags); |
1109 | 1108 | if (!list_empty(&coredev->buffers)) { | |
1110 | /* This function must return a valid buffer, since the buffer list is | 1109 | cb = (struct smscore_buffer_t *) coredev->buffers.next; |
1111 | * finite, we check that there is an available buffer, if not, we wait | 1110 | list_del(&cb->entry); |
1112 | * until such buffer become available. | ||
1113 | */ | ||
1114 | |||
1115 | prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE); | ||
1116 | if (list_empty(&coredev->buffers)) { | ||
1117 | spin_unlock_irqrestore(&coredev->bufferslock, flags); | ||
1118 | schedule(); | ||
1119 | spin_lock_irqsave(&coredev->bufferslock, flags); | ||
1120 | } | 1111 | } |
1112 | spin_unlock_irqrestore(&coredev->bufferslock, flags); | ||
1113 | return cb; | ||
1114 | } | ||
1121 | 1115 | ||
1122 | finish_wait(&coredev->buffer_mng_waitq, &wait); | 1116 | struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) |
1123 | 1117 | { | |
1124 | cb = (struct smscore_buffer_t *) coredev->buffers.next; | 1118 | struct smscore_buffer_t *cb = NULL; |
1125 | list_del(&cb->entry); | ||
1126 | 1119 | ||
1127 | spin_unlock_irqrestore(&coredev->bufferslock, flags); | 1120 | wait_event(coredev->buffer_mng_waitq, (cb = get_entry(coredev))); |
1128 | 1121 | ||
1129 | return cb; | 1122 | return cb; |
1130 | } | 1123 | } |