diff mbox series

[v2,4/4] rcar-csi2: Do not try to recover after transfer error

Message ID 20210115002148.4079591-5-niklas.soderlund+renesas@ragnatech.se
State Superseded
Headers show
Series rcar-csi2: Update handling of transfer error | expand

Commit Message

Niklas Söderlund Jan. 15, 2021, 12:21 a.m. UTC
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 stop the
whole pipeline and 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@ragnatech.se>
---
 drivers/media/platform/rcar-vin/rcar-csi2.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

Comments

Hans Verkuil Jan. 25, 2021, 9:44 a.m. UTC | #1
On 15/01/2021 01:21, Niklas Söderlund wrote:
> 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 stop the

> whole pipeline and 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@ragnatech.se>

> ---

>  drivers/media/platform/rcar-vin/rcar-csi2.c | 14 ++++++--------

>  1 file changed, 6 insertions(+), 8 deletions(-)

> 

> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c

> index 945d2eb8723367f0..a7212ecc46572a3b 100644

> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c

> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c

> @@ -773,21 +773,19 @@ 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_EOS,

> +	};

>  

> -	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);

> +	dev_err(priv->dev, "Transfer error detected.\n");


You probably want to call vb2_queue_error() here. Typically once
something like this happens you have to restart everything and marking
the queue as 'error' will ensure that VIDIOC_QBUF will return an error
until the queue is reset (STREAMOFF).

It doesn't hurt to also raise the EOS event, I'm fine with that.

Regards,

	Hans

> +

> +	v4l2_subdev_notify_event(&priv->subdev, &event);

>  

>  	return IRQ_HANDLED;

>  }

>
Niklas Söderlund March 10, 2021, 4:45 p.m. UTC | #2
Hi Hans,

Thanks for your feedback.

On 2021-01-25 10:44:48 +0100, Hans Verkuil wrote:
> On 15/01/2021 01:21, Niklas Söderlund wrote:

> > 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 stop the

> > whole pipeline and 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@ragnatech.se>

> > ---

> >  drivers/media/platform/rcar-vin/rcar-csi2.c | 14 ++++++--------

> >  1 file changed, 6 insertions(+), 8 deletions(-)

> > 

> > diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c

> > index 945d2eb8723367f0..a7212ecc46572a3b 100644

> > --- a/drivers/media/platform/rcar-vin/rcar-csi2.c

> > +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c

> > @@ -773,21 +773,19 @@ 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_EOS,

> > +	};

> >  

> > -	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);

> > +	dev_err(priv->dev, "Transfer error detected.\n");

> 

> You probably want to call vb2_queue_error() here. Typically once

> something like this happens you have to restart everything and marking

> the queue as 'error' will ensure that VIDIOC_QBUF will return an error

> until the queue is reset (STREAMOFF).


The CSI-2 driver is a bridge driver and does not deal with buffers.  
Instead the idea here is to signal EOS so that the VIN driver (and 
user-space) can detect it and indeed as you point out deal with 
signaling vb2 error.

I will respin this series as it needs to be rebased anyhow.

> 

> It doesn't hurt to also raise the EOS event, I'm fine with that.

> 

> Regards,

> 

> 	Hans

> 

> > +

> > +	v4l2_subdev_notify_event(&priv->subdev, &event);

> >  

> >  	return IRQ_HANDLED;

> >  }

> > 

> 


-- 
Regards,
Niklas Söderlund
diff mbox series

Patch

diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
index 945d2eb8723367f0..a7212ecc46572a3b 100644
--- a/drivers/media/platform/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
@@ -773,21 +773,19 @@  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_EOS,
+	};
 
-	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);
+	dev_err(priv->dev, "Transfer error detected.\n");
+
+	v4l2_subdev_notify_event(&priv->subdev, &event);
 
 	return IRQ_HANDLED;
 }