[media] coda: first step at error recovery

This implements a simple handler for the case where decode did not finish
sucessfully. This might be helpful during normal streaming, but for now it
only handles the case where the context would deadlock with userspace,
i.e. userspace issued DEC_CMD_STOP and waits for EOS, but after the failed
decode run we would hold the context and wait for userspace to queue more
buffers.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

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

@@ -2198,12 +2198,32 @@ static void coda_finish_decode(struct coda_ctx *ctx)
 	ctx->display_idx = display_idx;
 }
 
+static void coda_error_decode(struct coda_ctx *ctx)
+{
+	struct vb2_v4l2_buffer *dst_buf;
+
+	/*
+	 * For now this only handles the case where we would deadlock with
+	 * userspace, i.e. userspace issued DEC_CMD_STOP and waits for EOS,
+	 * but after a failed decode run we would hold the context and wait for
+	 * userspace to queue more buffers.
+	 */
+	if (!(ctx->bit_stream_param & CODA_BIT_STREAM_END_FLAG))
+		return;
+
+	dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
+	dst_buf->sequence = ctx->qsequence - 1;
+
+	coda_m2m_buf_done(ctx, dst_buf, VB2_BUF_STATE_ERROR);
+}
+
 const struct coda_context_ops coda_bit_decode_ops = {
 	.queue_init = coda_decoder_queue_init,
 	.reqbufs = coda_decoder_reqbufs,
 	.start_streaming = coda_start_decoding,
 	.prepare_run = coda_prepare_decode,
 	.finish_run = coda_finish_decode,
+	.error_run = coda_error_decode,
 	.seq_end_work = coda_seq_end_work,
 	.release = coda_bit_release,
 };

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

@@ -1163,6 +1163,9 @@ static void coda_pic_run_work(struct work_struct *work)
 		ctx->hold = true;
 
 		coda_hw_reset(ctx);
+
+		if (ctx->ops->error_run)
+			ctx->ops->error_run(ctx);
 	} else if (!ctx->aborting) {
 		ctx->ops->finish_run(ctx);
 	}

drivers/media/platform/coda/coda.h

@@ -183,6 +183,7 @@ struct coda_context_ops {
 	int (*start_streaming)(struct coda_ctx *ctx);
 	int (*prepare_run)(struct coda_ctx *ctx);
 	void (*finish_run)(struct coda_ctx *ctx);
+	void (*error_run)(struct coda_ctx *ctx);
 	void (*seq_end_work)(struct work_struct *work);
 	void (*release)(struct coda_ctx *ctx);
 };