From 3cdadc50bbe8f04c1231c8af614cafd7ddd622bf Mon Sep 17 00:00:00 2001 From: Richard Zidlicky Date: Tue, 24 Aug 2010 09:52:36 -0300 Subject: 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 Cc: stable@kernel.org Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/siano/smscoreapi.c | 31 ++++++++++++------------------- 1 file changed, 12 insertions(+), 19 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/dvb/siano/smscoreapi.c b/drivers/media/dvb/siano/smscoreapi.c index d93468c..ff3b0fa 100644 --- a/drivers/media/dvb/siano/smscoreapi.c +++ b/drivers/media/dvb/siano/smscoreapi.c @@ -1098,33 +1098,26 @@ EXPORT_SYMBOL_GPL(smscore_onresponse); * * @return pointer to descriptor on success, NULL on error. */ -struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) + +struct smscore_buffer_t *get_entry(struct smscore_device_t *coredev) { struct smscore_buffer_t *cb = NULL; unsigned long flags; - DEFINE_WAIT(wait); - spin_lock_irqsave(&coredev->bufferslock, flags); - - /* This function must return a valid buffer, since the buffer list is - * finite, we check that there is an available buffer, if not, we wait - * until such buffer become available. - */ - - prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE); - if (list_empty(&coredev->buffers)) { - spin_unlock_irqrestore(&coredev->bufferslock, flags); - schedule(); - spin_lock_irqsave(&coredev->bufferslock, flags); + if (!list_empty(&coredev->buffers)) { + cb = (struct smscore_buffer_t *) coredev->buffers.next; + list_del(&cb->entry); } + spin_unlock_irqrestore(&coredev->bufferslock, flags); + return cb; +} - finish_wait(&coredev->buffer_mng_waitq, &wait); - - cb = (struct smscore_buffer_t *) coredev->buffers.next; - list_del(&cb->entry); +struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) +{ + struct smscore_buffer_t *cb = NULL; - spin_unlock_irqrestore(&coredev->bufferslock, flags); + wait_event(coredev->buffer_mng_waitq, (cb = get_entry(coredev))); return cb; } -- cgit v1.1