[media] s5p-mfc: fix encoder crash after VIDIOC_STREAMOFF

VIDIOC_STREAMOFF clears the encoder's destination queue -- routines run
from the interrupt handler cannot assume that the queue is non-empty.

Signed-off-by: John Sheu <sheu@google.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
index 458279e5dc80..704e37c07903 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
@@ -772,13 +772,16 @@ static int enc_post_seq_start(struct s5p_mfc_ctx *ctx)
 
         if (p->seq_hdr_mode == V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE) {
                 spin_lock_irqsave(&dev->irqlock, flags);
-                dst_mb = list_entry(ctx->dst_queue.next,
-                                struct s5p_mfc_buf, list);
-                list_del(&dst_mb->list);
-                ctx->dst_queue_cnt--;
-                vb2_set_plane_payload(dst_mb->b, 0,
-                        s5p_mfc_hw_call(dev->mfc_ops, get_enc_strm_size, dev));
-                vb2_buffer_done(dst_mb->b, VB2_BUF_STATE_DONE);
+                if (!list_empty(&ctx->dst_queue)) {
+                        dst_mb = list_entry(ctx->dst_queue.next,
+                                        struct s5p_mfc_buf, list);
+                        list_del(&dst_mb->list);
+                        ctx->dst_queue_cnt--;
+                        vb2_set_plane_payload(dst_mb->b, 0,
+                                s5p_mfc_hw_call(dev->mfc_ops, get_enc_strm_size,
+                                                dev));
+                        vb2_buffer_done(dst_mb->b, VB2_BUF_STATE_DONE);
+                }
                 spin_unlock_irqrestore(&dev->irqlock, flags);
         }
 
@@ -883,8 +886,7 @@ static int enc_post_frame_start(struct s5p_mfc_ctx *ctx)
                 mfc_debug(2, "enc src count: %d, enc ref count: %d\n",
                           ctx->src_queue_cnt, ctx->ref_queue_cnt);
         }
-        if (strm_size > 0) {
-                /* at least one more dest. buffers exist always  */
+        if ((ctx->dst_queue_cnt > 0) && (strm_size > 0)) {
                 mb_entry = list_entry(ctx->dst_queue.next, struct s5p_mfc_buf,
                                                                         list);
                 list_del(&mb_entry->list);