From: Philipp Zabel Date: Thu, 24 Oct 2019 10:32:11 +0000 (-0300) Subject: media: coda: fix deadlock between decoder picture run and start command X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a3fd80198de6ab98a205cf7fb148d88e9e1c44bb;p=linux.git media: coda: fix deadlock between decoder picture run and start command 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 Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c index 73222c0615c0c..834f11fe9dc29 100644 --- 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 *file, void *fh, 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;