From 03915a22e801e9709146f11619534e22a7338614 Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Thu, 24 Oct 2019 07:32:11 -0300 Subject: [PATCH] media: coda: fix deadlock between decoder picture run and start command 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 Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/platform/coda/coda-common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c index 73222c0615c0..834f11fe9dc2 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;