From 48c01a9c2d245b229f8b709040cb1776b00dc683 Mon Sep 17 00:00:00 2001 From: Andrea Odetti Date: Sun, 20 Apr 2008 18:37:45 -0300 Subject: [PATCH] V4L/DVB (7658): dvb-core: Fix DMX_SET_BUFFER_SIZE in case the buffer shrinks 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 Signed-off-by: Oliver Endriss Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/dvb-core/dmxdev.c | 4 +++- drivers/media/dvb/dvb-core/dvb_ringbuffer.c | 6 +++++- drivers/media/dvb/dvb-core/dvb_ringbuffer.h | 8 ++++++++ 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c index 3415a3bb36..bbd52be552 100644 --- a/drivers/media/dvb/dvb-core/dmxdev.c +++ b/drivers/media/dvb/dvb-core/dmxdev.c @@ -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); diff --git a/drivers/media/dvb/dvb-core/dvb_ringbuffer.c b/drivers/media/dvb/dvb-core/dvb_ringbuffer.c index ac9d93cf83..872985b791 100644 --- a/drivers/media/dvb/dvb-core/dvb_ringbuffer.c +++ b/drivers/media/dvb/dvb-core/dvb_ringbuffer.c @@ -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) { diff --git a/drivers/media/dvb/dvb-core/dvb_ringbuffer.h b/drivers/media/dvb/dvb-core/dvb_ringbuffer.h index d97714e757..8908262629 100644 --- a/drivers/media/dvb/dvb-core/dvb_ringbuffer.h +++ b/drivers/media/dvb/dvb-core/dvb_ringbuffer.h @@ -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 */ -- 2.39.5