Re: [PATCH v3 3/3] media: atmel-isi: add sanity check for supported formats in try/set_fmt()

[Josh Wu <josh.wu@xxxxxxxxx>]

Hi, Laurent

On 8/22/2015 2:22 AM, Laurent Pinchart wrote:
> Hi Josh,
>
> Thank you for the patch.
>
> On Friday 21 August 2015 16:08:14 Josh Wu wrote:
> > After adding the format check in try_fmt()/set_fmt(), we don't need any
> > format check in configure_geometry(). So make configure_geometry() as
> > void type.
> >
> > Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
> > ---
> >
> > Changes in v3:
> > - check the whether format is supported, if no then return a default
> >    format.
> > - misc changes according to Laurent's feedback.
> >
> > Changes in v2:
> > - new added patch
> >
> >   drivers/media/platform/soc_camera/atmel-isi.c | 37 ++++++++++++++++++------
> >   1 file changed, 29 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/media/platform/soc_camera/atmel-isi.c
> > b/drivers/media/platform/soc_camera/atmel-isi.c index fe9247a..84c91d3
> > 100644
> > --- a/drivers/media/platform/soc_camera/atmel-isi.c
> > +++ b/drivers/media/platform/soc_camera/atmel-isi.c
> > @@ -102,17 +102,19 @@ static u32 isi_readl(struct atmel_isi *isi, u32 reg)
> >   	return readl(isi->regs + reg);
> >   }
> >
> > -static int configure_geometry(struct atmel_isi *isi, u32 width,
> > +static void configure_geometry(struct atmel_isi *isi, u32 width,
> >   			u32 height, u32 code)
> >   {
> >   	u32 cfg2;
> >
> >   	/* According to sensor's output format to set cfg2 */
> >   	switch (code) {
> > -	/* YUV, including grey */
> > +	default:
> > +	/* Grey */
> >   	case MEDIA_BUS_FMT_Y8_1X8:
> >   		cfg2 = ISI_CFG2_GRAYSCALE;
> >   		break;
> > +	/* YUV */
> >   	case MEDIA_BUS_FMT_VYUY8_2X8:
> >   		cfg2 = ISI_CFG2_YCC_SWAP_MODE_3;
> >   		break;
> > @@ -126,8 +128,6 @@ static int configure_geometry(struct atmel_isi *isi, u32
> > width, cfg2 = ISI_CFG2_YCC_SWAP_DEFAULT;
> >   		break;
> >   	/* RGB, TODO */
> > -	default:
> > -		return -EINVAL;
> >   	}
> >
> >   	isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
> > @@ -138,8 +138,23 @@ static int configure_geometry(struct atmel_isi *isi,
> > u32 width, cfg2 |= ((height - 1) << ISI_CFG2_IM_VSIZE_OFFSET)
> >   			& ISI_CFG2_IM_VSIZE_MASK;
> >   	isi_writel(isi, ISI_CFG2, cfg2);
> > +}
> >
> > -	return 0;
> > +static bool is_supported(struct soc_camera_device *icd,
> > +		const u32 pixformat)
> > +{
> > +	switch (pixformat) {
> > +	/* YUV, including grey */
> > +	case V4L2_PIX_FMT_GREY:
> > +	case V4L2_PIX_FMT_YUYV:
> > +	case V4L2_PIX_FMT_UYVY:
> > +	case V4L2_PIX_FMT_YVYU:
> > +	case V4L2_PIX_FMT_VYUY:
> > +		return true;
> > +	/* RGB, TODO */
> > +	default:
> > +		return false;
> > +	}
> >   }
> >
> >   static irqreturn_t atmel_isi_handle_streaming(struct atmel_isi *isi)
> > @@ -390,10 +405,8 @@ static int start_streaming(struct vb2_queue *vq,
> > unsigned int count) /* Disable all interrupts */
> >   	isi_writel(isi, ISI_INTDIS, (u32)~0UL);
> >
> > -	ret = configure_geometry(isi, icd->user_width, icd->user_height,
> > +	configure_geometry(isi, icd->user_width, icd->user_height,
> >   				icd->current_fmt->code);
> > -	if (ret < 0)
> > -		return ret;
> >
> >   	spin_lock_irq(&isi->lock);
> >   	/* Clear any pending interrupt */
> > @@ -491,6 +504,10 @@ static int isi_camera_set_fmt(struct soc_camera_device
> > *icd, struct v4l2_mbus_framefmt *mf = &format.format;
> >   	int ret;
> >
> > +	/* check with atmel-isi support format, if not support use UYVY */
> > +	if (!is_supported(icd, pix->pixelformat))
> > +		pix->pixelformat = V4L2_PIX_FMT_YUYV;
> The comment mentions UYVY and the code uses YUYV.

Oops, forgotten to change the comments. I'll fix it.
> > +
> >   	xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
> >   	if (!xlate) {
> >   		dev_warn(icd->parent, "Format %x not found\n",
> Can this still happen ?

I think this warning should not happen if user call set_fmt() with the 
format that get from by get_formats().
But it is a common pattern in soc_camera host code to handle this error.

> > @@ -540,6 +557,10 @@ static int isi_camera_try_fmt(struct soc_camera_device
> > *icd, u32 pixfmt = pix->pixelformat;
> >   	int ret;
> >
> > +	/* check with atmel-isi support format, if not support use UYVY */
> > +	if (!is_supported(icd, pix->pixelformat))
> > +		pix->pixelformat = V4L2_PIX_FMT_YUYV;
> > +
> >   	xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
> >   	if (pixfmt && !xlate) {
> >   		dev_warn(icd->parent, "Format %x not found\n", pixfmt);
> Same comment here.
>
> I wonder whether most of the content of isi_camera_set_fmt() and
> isi_camera_try_fmt() could be factorized out into a shared function.

I agree. the current set_fmt() doesn't touch any hardware, so it's 
almost same as try_fmt().

Best Regards,
Josh Wu
>

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