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V4L/DVB (7658): dvb-core: Fix DMX_SET_BUFFER_SIZE in case the buffer shrinks

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This patch fixes the bug in DMX_SET_BUFFER_SIZE for the demux.
Basically it resets read and write pointers to 0 in case they are
beyond the new size of the buffer.

Signed-off-by: Andrea Odetti <mariofutire@gmail.com>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Andrea Odetti 2008-04-20 18:37:45 -03:00 committed by Mauro Carvalho Chehab
parent 3ff9a81b21
commit 48c01a9c2d
3 changed files with 16 additions and 2 deletions
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4
drivers/media/dvb/dvb-core/dmxdev.c
View file

@ -281,7 +281,9 @@ static int dvb_dmxdev_set_buffer_size(struct dmxdev_filter *dmxdevfilter,
mem = buf->data;
buf->data = NULL;
buf->size = size;
dvb_ringbuffer_flush(buf);
/* reset and not flush in case the buffer shrinks */
dvb_ringbuffer_reset(buf);
spin_unlock_irq(&dmxdevfilter->dev->lock);
vfree(mem);

6
drivers/media/dvb/dvb-core/dvb_ringbuffer.c
View file

@ -90,7 +90,11 @@ void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf)
rbuf->error = 0;
}
void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf)
{
rbuf->pread = rbuf->pwrite = 0;
rbuf->error = 0;
}
void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf)
{

8
drivers/media/dvb/dvb-core/dvb_ringbuffer.h
View file

@ -69,6 +69,7 @@ struct dvb_ringbuffer {
** to lock read or write operations.
** Two or more readers must be locked against each other.
** Flushing the buffer counts as a read operation.
** Resetting the buffer counts as a read and write operation.
** Two or more writers must be locked against each other.
*/
@ -85,6 +86,13 @@ extern ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf);
extern ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf);
/*
** Reset the read and write pointers to zero and flush the buffer
** This counts as a read and write operation
*/
extern void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf);
/* read routines & macros */
/* ---------------------- */
/* flush buffer */