Re: [PATCH 1/2] media: ov5640: Fix timings setup code

[jacopo mondi <jacopo@jmondi.org>]

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Hi Hugues,
   I'll reply to your v2 series shortly, but let me point out one
thing before.

+steve

On Tue, Aug 07, 2018 at 08:53:53AM +0000, Hugues FRUCHET wrote:
> Hi Jacopo,
>
> Thanks for this patch, when testing on my side I don't see special
> regression or enhancement with that fix, particularly on image quality
> (exposure, ...),

On imx.6 platforms I need this patch along with the MIPI interface
setup fixes sent here [1] to have capture working.

I messed up a bit, as I've sent the "timings fixes" in two series,
this one I'm replying to and the one I've pasted the link of, even if
those series had two different purposes.

So, this patch in my setup does not fixes an image quality issues, but
instead takes part in solving a problems with MIPI CSI-2 on imx.6
platforms.

I asked Steve Longerbeam to test on his imx.6 platform and he reported
his issues was not fixed and he got blank frames ( I was very
disappointed by the different results we had, but moved on and kept
carrying those patches in my tree, as otherwise MIPI interface failed
to startup).

Now I have asked Steve if he might have blank frames, which might be
an exposure related issue, I never had as I skept the first frames,
which are usually the blank one (you're cc-ed).

I believe too your exposure+gain series should be applied and
should supersed [2/2] of this series, but this timing fix is necessary
for me, and I hope Steve's problem are related to exposure handling
issues your series might fix as it did for me.

> do you have a test procedure that underline the issue ?
> For example on my side when I do 5Mp then QVGA capture, pictures are
> overexposed/greenish:

I do capture with yavta, I usually skept the first 7 frames and then
captured 3. Without exposure fix (my patch or your series) the first
frames are black.

This driver is making our life miserable, isn't it? :)

Thanks
   j

[1] https://www.spinics.net/lists/linux-media/msg137557.html

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