Re: [PATCH 1/2] media: i2c: ov5645: Move the register 0x3008 from ov5645_global_init_setting

[Wolfram Sang <wsa@kernel.org>]

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Hi Biju,

I couldn't find a datasheet for the OV5645 but the one for OV5642 looked
pretty similar when it comes to the issues mentioned here.

> Testing OV5645 with i2c bus frequency @400kHz on RZ/G2L SMARC EVL platform
> shows issues like the captured image is either greenish or it is not
> capturing the image at all. However, It is working ok when the i2c
> frequency is 100kHz. From this, it is clear that we have a timing issue
> at high speed. The testing also shows that if we add a delay >= 1 msec

That could match the "VDD stable to sensor stable" delay in the
datasheet.

> after register write {0x3008, 0x82}, then the captured image is always
> good. So, move the register 0x3008 and 0x3103 from ov5645_*_init_setting
> to a new table ov5645_global_init_setting.
> 
> Drop the unnecessary entry { 0x3008, 0x42 } from ov5645_*init_setting
> table at the start.

It seems this is not needed to fix your issue? Then, this would be a
seperate change with a dedicated reason, I'd think. There is another
pair of activating power-down mode and immediately disabling it again.
Either we simplify it, too, or we leave both in place. Or at least make
sure there wasn't a reason for them. I'd just leave them.

Rest looks good to me.

Happy hacking,

   Wolfram


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