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>
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@ -1098,33 +1098,26 @@ EXPORT_SYMBOL_GPL(smscore_onresponse);
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*
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* @return pointer to descriptor on success, NULL on error.
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*/
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struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev)
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struct smscore_buffer_t *get_entry(struct smscore_device_t *coredev)
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{
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struct smscore_buffer_t *cb = NULL;
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unsigned long flags;
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DEFINE_WAIT(wait);
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spin_lock_irqsave(&coredev->bufferslock, flags);
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/* This function must return a valid buffer, since the buffer list is
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* finite, we check that there is an available buffer, if not, we wait
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* until such buffer become available.
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*/
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prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE);
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if (list_empty(&coredev->buffers)) {
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spin_unlock_irqrestore(&coredev->bufferslock, flags);
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schedule();
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spin_lock_irqsave(&coredev->bufferslock, flags);
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if (!list_empty(&coredev->buffers)) {
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cb = (struct smscore_buffer_t *) coredev->buffers.next;
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list_del(&cb->entry);
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}
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finish_wait(&coredev->buffer_mng_waitq, &wait);
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cb = (struct smscore_buffer_t *) coredev->buffers.next;
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list_del(&cb->entry);
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spin_unlock_irqrestore(&coredev->bufferslock, flags);
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return cb;
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}
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struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev)
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{
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struct smscore_buffer_t *cb = NULL;
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wait_event(coredev->buffer_mng_waitq, (cb = get_entry(coredev)));
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return cb;
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}
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