linux-kernel - [PATCH v2 4/4] rkvdec: Improve error handling

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Date:   Fri, 23 Dec 2022 14:38:06 -0500
From:   Nicolas Dufresne <nicolas.dufresne@...labora.com>
To:     Ezequiel Garcia <ezequiel@...guardiasur.com.ar>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     kernel@...labora.com,
        Nicolas Dufresne <nicolas.dufresne@...labora.com>,
        linux-media@...r.kernel.org, linux-rockchip@...ts.infradead.org,
        linux-staging@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: [PATCH v2 4/4] rkvdec: Improve error handling

There are two ways decoding errors can occure. In one case, the ready
status is not set and nothing has been written into the destination,
while in the other case, the buffer is written but may contain a
certain amount of errors. In order to differentiate these, we set
the payload for the first case to 0.

Signed-off-by: Nicolas Dufresne <nicolas.dufresne@...labora.com>
---
 drivers/staging/media/rkvdec/rkvdec.c | 31 +++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c
index 7e76f8b728854..11e2bbb20aea1 100644
--- a/drivers/staging/media/rkvdec/rkvdec.c
+++ b/drivers/staging/media/rkvdec/rkvdec.c
@@ -27,6 +27,9 @@
 #include "rkvdec.h"
 #include "rkvdec-regs.h"
 
+static int debug;
+module_param(debug, int, 0644);
+
 static int rkvdec_try_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct rkvdec_ctx *ctx = container_of(ctrl->handler, struct rkvdec_ctx, ctrl_hdl);
@@ -954,14 +957,34 @@ static irqreturn_t rkvdec_irq_handler(int irq, void *priv)
 	enum vb2_buffer_state state;
 	u32 status;
 
+	ctx = v4l2_m2m_get_curr_priv(rkvdec->m2m_dev);
 	status = readl(rkvdec->regs + RKVDEC_REG_INTERRUPT);
-	state = (status & RKVDEC_RDY_STA) ?
-		VB2_BUF_STATE_DONE : VB2_BUF_STATE_ERROR;
+
+	if (!(status & RKVDEC_RDY_STA)) {
+		struct vb2_v4l2_buffer *dst_buf = NULL;
+
+		if (status & RKVDEC_TIMEOUT_STA)
+			v4l2_dbg(debug, 1, &rkvdec->v4l2_dev,
+				 "Decoder stopped due to an internal timeout.");
+		else
+			v4l2_dbg(debug, 1, &rkvdec->v4l2_dev,
+				 "Decoder stopped due to an internal error.");
+
+		/*
+		 * When this happens, the buffer is left unmodified. As it
+		 * contains no meaningful data we mark is as empty.
+		 */
+		dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
+		vb2_set_plane_payload(&dst_buf->vb2_buf, 0, 0);
+		state = VB2_BUF_STATE_ERROR;
+	} else {
+		state = VB2_BUF_STATE_DONE;
+	}
 
 	writel(0, rkvdec->regs + RKVDEC_REG_INTERRUPT);
-	ctx = v4l2_m2m_get_curr_priv(rkvdec->m2m_dev);
 
-	if (ctx->coded_fmt_desc->ops->check_error_info)
+	if (ctx->coded_fmt_desc->ops->check_error_info &&
+	    state == VB2_BUF_STATE_DONE)
 		state = ctx->coded_fmt_desc->ops->check_error_info(ctx);
 
 	if (cancel_delayed_work(&rkvdec->watchdog_work))
-- 
2.38.1