Re: [PATCH] media: i.MX27 camera: fix picture source width

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Feb 15, 2013 at 06:08:41PM +0100, Christoph Fritz wrote:
> While using a mt9m001 (monochrome) camera the final output falsely gets
> horizontally divided into two pictures.
> 
> The issue was git bisected to commit f410991dcf1f
> 
>   |  [media] i.MX27 camera: add support for YUV420 format
>   |
>   |  This patch uses channel 2 of the eMMa-PrP to convert
>   |  format provided by the sensor to YUV420.
>   |
>   |  This format is very useful since it is used by the
>   |  internal H.264 encoder.
> 
> It sets PICTURE_X_SIZE in register PRP_SRC_FRAME_SIZE to its full width
> while before that commit it was divided by two:
> 
> -   writel(((bytesperline >> 1) << 16) | icd->user_height,
> +           writel((icd->user_width << 16) | icd->user_height,
>                     pcdev->base_emma + PRP_SRC_FRAME_SIZE);
> 
> i.mx27 reference manual (41.6.12 PrP Source Frame Size Register) says:
> 
>     PICTURE_X_SIZE. These bits set the frame width to be
>     processed in number of pixels. In YUV 4:2:0 mode, Cb and
>     Cr widths are taken as PICTURE_X_SIZE/2 pixels.  In YUV
>     4:2:0 mode, this value should be a multiple of 8-pixels.
>     In other modes (RGB, YUV 4:2:2 and YUV 4:4:4) it should
>     be a multiple of 4 pixels.
> 
> This patch reverts to PICTURE_X_SIZE/2 for channel 1.
> 
> Tested on Kernel 3.4, merged to 3.8rc.
> 
> Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com>
> ---
>  drivers/media/platform/soc_camera/mx2_camera.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

</formletter>