From: Philipp Zabel p.zabel@pengutronix.de
commit a3fd80198de6ab98a205cf7fb148d88e9e1c44bb upstream.
The BIT decoder picture run temporarily locks the bitstream mutex while the coda device mutex is locked, to refill the bitstream ring buffer. Consequently, the decoder start command, which locks both mutexes when flushing the bitstream ring buffer, must lock the coda device mutex first as well, to avoid an ABBA deadlock.
Fixes: e7fd95849b3c ("media: coda: flush bitstream ring buffer on decoder restart") Signed-off-by: Philipp Zabel p.zabel@pengutronix.de Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/platform/coda/coda-common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/media/platform/coda/coda-common.c +++ b/drivers/media/platform/coda/coda-common.c @@ -1084,16 +1084,16 @@ static int coda_decoder_cmd(struct file
switch (dc->cmd) { case V4L2_DEC_CMD_START: - mutex_lock(&ctx->bitstream_mutex); mutex_lock(&dev->coda_mutex); + mutex_lock(&ctx->bitstream_mutex); coda_bitstream_flush(ctx); - mutex_unlock(&dev->coda_mutex); dst_vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE); vb2_clear_last_buffer_dequeued(dst_vq); ctx->bit_stream_param &= ~CODA_BIT_STREAM_END_FLAG; coda_fill_bitstream(ctx, NULL); mutex_unlock(&ctx->bitstream_mutex); + mutex_unlock(&dev->coda_mutex); break; case V4L2_DEC_CMD_STOP: stream_end = false;