media: coda: lock capture queue wakeup against decoder stop command

Similar to commit 9ee50a94 ("media: coda: lock capture queue wakeup
against encoder stop command"), make sure that a JPEG decoder stop
command running concurrently with a decoder finish_run always either
flags the last returned buffer or wakes up the capture queue to signal
the end of stream condition afterwards.

This was not necessary for BIT processor contexts because of the need to
release the bitstream buffer with the stream end condition. In contrast,
the JPEG decoder can be finished with decoding the image between the
time the application queues the last output buffer and the time it
issues the decoder stop command.
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+huawei@kernel.org>

drivers/media/platform/coda/coda-common.c

@@ -1230,6 +1230,8 @@ static int coda_decoder_cmd(struct file *file, void *fh,
 		stream_end = false;
 		wakeup = false;
 
+		mutex_lock(&ctx->wakeup_mutex);
+
 		buf = v4l2_m2m_last_src_buf(ctx->fh.m2m_ctx);
 		if (buf) {
 			coda_dbg(1, ctx, "marking last pending buffer\n");
@@ -1266,6 +1268,7 @@ static int coda_decoder_cmd(struct file *file, void *fh,
 			coda_wake_up_capture_queue(ctx);
 		}
 
+		mutex_unlock(&ctx->wakeup_mutex);
 		break;
 	default:
 		return -EINVAL;

drivers/media/platform/coda/coda-jpeg.c

@@ -1428,6 +1428,12 @@ static void coda9_jpeg_finish_decode(struct coda_ctx *ctx)
 
 	coda_write(dev, 0, CODA9_REG_JPEG_BBC_FLUSH_CMD);
 
+	/*
+	 * Lock to make sure that a decoder stop command running in parallel
+	 * will either already have marked src_buf as last, or it will wake up
+	 * the capture queue after the buffers are returned.
+	 */
+	mutex_lock(&ctx->wakeup_mutex);
 	src_buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
 	dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
 	dst_buf->sequence = ctx->osequence++;
@@ -1447,6 +1453,8 @@ static void coda9_jpeg_finish_decode(struct coda_ctx *ctx)
 	coda_m2m_buf_done(ctx, dst_buf, err_mb ? VB2_BUF_STATE_ERROR :
 						 VB2_BUF_STATE_DONE);
 
+	mutex_unlock(&ctx->wakeup_mutex);
+
 	coda_dbg(1, ctx, "job finished: decoded frame (%u)%s\n",
 		 dst_buf->sequence,
 		 (dst_buf->flags & V4L2_BUF_FLAG_LAST) ? " (last)" : "");