Re: [PATCH v3 03/12] media: ov5640: Remove the clocks registers initialization

[Daniel Mack <daniel@zonque.org>]

Hi Maxime,

On Tuesday, May 22, 2018 09:54 PM, Maxime Ripard wrote:
> On Mon, May 21, 2018 at 09:39:02AM +0200, Maxime Ripard wrote:
>> On Fri, May 18, 2018 at 07:42:34PM -0700, Sam Bobrowicz wrote:

>>> This set of patches is also not working for my MIPI platform (mine has
>>> a 12 MHz external clock). I am pretty sure is isn't working because it
>>> does not include the following, which my tests have found to be
>>> necessary:
>>>
>>> 1) Setting pclk period reg in order to correct DPHY timing.
>>> 2) Disabling of MIPI lanes when streaming not enabled.
>>> 3) setting mipi_div to 1 when the scaler is disabled
>>> 4) Doubling ADC clock on faster resolutions.
>>
>> Yeah, I left them out because I didn't think this was relevant to this
>> patchset but should come as future improvements. However, given that
>> it works with the parallel bus, maybe the two first are needed when
>> adjusting the rate.
> 
> I've checked for the pclk period, and it's hardcoded to the same value
> all the time, so I guess this is not the reason it doesn't work on
> MIPI CSI anymore.
> 
> Daniel, could you test:
> http://code.bulix.org/ki6kgz-339327?raw

[Note that there's a missing parenthesis in this snippet]

Hmm, no, that doesn't change anything. Streaming doesn't work here, even 
if I move ov5640_load_regs() before any other initialization.

One of my test setup is the following gst pipeline:

   gst-launch-1.0	\
	v4l2src device=/dev/video0 ! \
	videoconvert ! \
	video/x-raw,format=UYVY,width=1920,height=1080 ! \
	glimagesink

With the pixel clock hard-coded to 166600000 in qcom camss, the setup 
works on 4.14, but as I said, it broke already before this series with 
5999f381e023 ("media: ov5640: Add horizontal and vertical
totals").

Frankly, my understanding of these chips is currently limited, so I 
don't really know where to start digging. It seems clear though that the 
timing registers setup is necessary for other register writes to succeed.

Can I help in any other way?


Thanks for all your efforts,
Daniel