[PATCH 2/3] rcar-csi2: Do not try to recover after transfer error

From: Michael Rodin
Date: Tue Jun 28 2022 - 14:01:35 EST


From: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>

Instead of restarting the R-Car CSI-2 receiver if a transmission error
is detected, inform the R-Car VIN driver of the error so it can inform
user-space. This is done to reflect a updated usage recommendation in later
versions of the datasheet.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Reviewed-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
[mrodin@xxxxxxxxxxxxxx: removed the statement about stopping the pipeline from the commit message]
Signed-off-by: Michael Rodin <mrodin@xxxxxxxxxxxxxx>
---
.../media/platform/renesas/rcar-vin/rcar-csi2.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/renesas/rcar-vin/rcar-csi2.c b/drivers/media/platform/renesas/rcar-vin/rcar-csi2.c
index fea8f00a9152..5a6494167c82 100644
--- a/drivers/media/platform/renesas/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/renesas/rcar-vin/rcar-csi2.c
@@ -943,21 +943,22 @@ static irqreturn_t rcsi2_irq(int irq, void *data)

rcsi2_write(priv, INTERRSTATE_REG, err_status);

- dev_info(priv->dev, "Transfer error, restarting CSI-2 receiver\n");
-
return IRQ_WAKE_THREAD;
}

static irqreturn_t rcsi2_irq_thread(int irq, void *data)
{
struct rcar_csi2 *priv = data;
+ struct v4l2_event event = {
+ .type = V4L2_EVENT_XFER_ERROR,
+ };

- mutex_lock(&priv->lock);
- rcsi2_stop(priv);
- usleep_range(1000, 2000);
- if (rcsi2_start(priv))
- dev_warn(priv->dev, "Failed to restart CSI-2 receiver\n");
- mutex_unlock(&priv->lock);
+ /* Disable further interrupts to not spam the transfer error event. */
+ rcsi2_write(priv, INTEN_REG, 0);
+
+ dev_err(priv->dev, "Transfer error detected.\n");
+
+ v4l2_subdev_notify_event(&priv->subdev, &event);

return IRQ_HANDLED;
}
--
2.25.1