diff options
| author | Soeren Moch <smoch@web.de> | 2013-06-05 21:26:23 -0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-07-27 05:34:13 +0100 |
| commit | 2af951daef68fcb1c6cace0543c420a8c26fe756 (patch) | |
| tree | 360eaf6edd44769c8cbc5ee03ae93290962ed3d8 /drivers/media | |
| parent | e4af376d04b03ff3ab2f27701bb183da6ee2aaff (diff) | |
media: dmxdev: remove dvb_ringbuffer_flush() on writer side
commit 414abbd2cd4c2618895f02ed3a76ec6647281436 upstream.
In dvb_ringbuffer lock-less synchronizationof reader and writer threads is done
with separateread and write pointers. Sincedvb_ringbuffer_flush() modifies the
read pointer, this function must not be called from the writer thread.
This patch removes the dvb_ringbuffer_flush() calls in the dmxdev ringbuffer
write functions, this fixes Oopses "Unable to handle kernel paging request"
I could observe for the call chaindvb_demux_read ->dvb_dmxdev_buffer_read ->
dvb_ringbuffer_read_user -> __copy_to_user (the reader side of the ringbuffer).
The flush calls at the write side are not necessary anyway since ringbuffer_flush
is also called in dvb_dmxdev_buffer_read() when an error condition is set in the
ringbuffer.
This patch should also be applied to stable kernels.
Signed-off-by: Soeren Moch <smoch@web.de>
Reviewed-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/dvb/dvb-core/dmxdev.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c index e4b5c03ae516..4f8c3f7281b4 100644 --- a/drivers/media/dvb/dvb-core/dmxdev.c +++ b/drivers/media/dvb/dvb-core/dmxdev.c @@ -380,10 +380,8 @@ static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len, ret = dvb_dmxdev_buffer_write(&dmxdevfilter->buffer, buffer2, buffer2_len); } - if (ret < 0) { - dvb_ringbuffer_flush(&dmxdevfilter->buffer); + if (ret < 0) dmxdevfilter->buffer.error = ret; - } if (dmxdevfilter->params.sec.flags & DMX_ONESHOT) dmxdevfilter->state = DMXDEV_STATE_DONE; spin_unlock(&dmxdevfilter->dev->lock); @@ -419,10 +417,8 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len, ret = dvb_dmxdev_buffer_write(buffer, buffer1, buffer1_len); if (ret == buffer1_len) ret = dvb_dmxdev_buffer_write(buffer, buffer2, buffer2_len); - if (ret < 0) { - dvb_ringbuffer_flush(buffer); + if (ret < 0) buffer->error = ret; - } spin_unlock(&dmxdevfilter->dev->lock); wake_up(&buffer->queue); return 0; |