An earlier commit "[media] V4L: sh_mobile_ceu_camera: convert to the new
mbus-config subdev operations" has inadvertantly removed the check in the
sh-mobile-ceu-camera driver, whether a specific bus-width is supported.
This patch restores the check for formats, requiring wider than 8-bit
video bus. The other check from the above commit - whether 8-bits per
sample are supported - is, however, not restored. All currently known set
ups support 8 bits per sample, hence, this check so far seems redundant.
The respective SH_CEU_FLAG_USE_8BIT_BUS flag will be kept for now, but may
be removed in the future.
Signed-off-by: Guennadi Liakhovetski
---
On Mon, 23 Apr 2012, Kuninori Morimoto wrote:
>
> Hi Guennadi
>
> Thanks for reply.
>
> > AFAICS, all these platforms only use 8 bits, so, none of them is broken.
> > OTOH, I'm not sure any more, what was the motivation behind that removal.
> > Maybe exactly because we didn't have any platforms with 16-bit camera
> > connections and maybe I saw a problem with it, so, I decided to remove
> > them until we get a chance to properly implement and test 16-bits? Do you
> > have such a board?
>
> about 16bit camera, one guy has it, but he is using v3.0 kernel,
> so, it is not in trouble at this point.
> (it is working)
>
> The motivation was just "misunderstand-able", not super important at this
> point.
> So please keep considering about it.
Would be nice if the below patch could be tested with a 16-bit set up. But
it should be tested "negatively." This means: I think, also now 16-bit set
ups work. The only problem is, that even if your board only connects 8
data lines, an attempt to set a 16-bit format wouldn't fail and would,
probably, deliver corrupt data. So, the test would be:
- take a 16-bit set up and choose a 16-bit format - it should work
- remove the 16-bit flag from the platform data - it would, presumably,
still work, which is a bug
- apply the patch
- now verify that 16-bits formats can only be used, if the board specifies
the respective flag in platform data
Thanks
Guennadi
diff --git a/drivers/media/video/sh_mobile_ceu_camera.c
b/drivers/media/video/sh_mobile_ceu_camera.c
index 424dfac..3e7b794 100644
--- a/drivers/media/video/sh_mobile_ceu_camera.c
+++ b/drivers/media/video/sh_mobile_ceu_camera.c
@@ -951,7 +951,8 @@ static int sh_mobile_ceu_try_bus_param(struct
soc_camera_device *icd,
else if (ret != -ENOIOCTLCMD)
return ret;
- if (!common_flags || buswidth > 16)
+ if (!common_flags || buswidth > 16 ||
+ (buswidth > 8 && !(pcdev->pdata->flags &
SH_CEU_FLAG_USE_16BIT_BUS)))
return -EINVAL;
return 0;
--
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