* pxa_camera + ov9655: image shifted on first capture after reset
@ 2010-04-16 8:25 Stefan Herbrechtsmeier
2010-04-16 10:07 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Stefan Herbrechtsmeier @ 2010-04-16 8:25 UTC (permalink / raw)
To: Guennadi Liakhovetski; +Cc: Linux Media Mailing List
Hi,
I have updated my ov9655 driver to kernel 2.6.33 and
did some test regarding the image shift problem on pxa.
(http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/10773/focus=11810)
- The image was shifted 32 pixels (64 bytes) to the right
or rather the first 32 pixels belongs to the previous image.
- The image was only shifted on the first capture after reset.
It doesn't matter whether I previous change the resolution with v4l2-ctl.
- On big images (1280 x 1024) the shift disappears after some images,
but not on small images (320 x 240).
It looks like the FIFO was not cleared at start capture.
Regards,
Stefan
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: pxa_camera + ov9655: image shifted on first capture after reset
2010-04-16 8:25 pxa_camera + ov9655: image shifted on first capture after reset Stefan Herbrechtsmeier
@ 2010-04-16 10:07 ` Jonathan Cameron
2010-04-19 13:15 ` Stefan Herbrechtsmeier
0 siblings, 1 reply; 3+ messages in thread
From: Jonathan Cameron @ 2010-04-16 10:07 UTC (permalink / raw)
To: Stefan Herbrechtsmeier; +Cc: Guennadi Liakhovetski, Linux Media Mailing List
On 04/16/10 09:25, Stefan Herbrechtsmeier wrote:
> Hi,
>
> I have updated my ov9655 driver to kernel 2.6.33 and
> did some test regarding the image shift problem on pxa.
> (http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/10773/focus=11810)
>
>
> - The image was shifted 32 pixels (64 bytes) to the right
> or rather the first 32 pixels belongs to the previous image.
> - The image was only shifted on the first capture after reset.
> It doesn't matter whether I previous change the resolution with v4l2-ctl.
> - On big images (1280 x 1024) the shift disappears after some images,
> but not on small images (320 x 240).
>
> It looks like the FIFO was not cleared at start capture.
>
Sounds reasonable. Similar problem seen with ov7670 attached to pxa271.
I've never taken the time to try and track it down.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: pxa_camera + ov9655: image shifted on first capture after reset
2010-04-16 10:07 ` Jonathan Cameron
@ 2010-04-19 13:15 ` Stefan Herbrechtsmeier
0 siblings, 0 replies; 3+ messages in thread
From: Stefan Herbrechtsmeier @ 2010-04-19 13:15 UTC (permalink / raw)
To: Jonathan Cameron; +Cc: Guennadi Liakhovetski, Linux Media Mailing List
Jonathan Cameron schrieb:
> On 04/16/10 09:25, Stefan Herbrechtsmeier wrote:
>
>> Hi,
>>
>> I have updated my ov9655 driver to kernel 2.6.33 and
>> did some test regarding the image shift problem on pxa.
>> (http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/10773/focus=11810)
>>
>>
>> - The image was shifted 32 pixels (64 bytes) to the right
>> or rather the first 32 pixels belongs to the previous image.
>> - The image was only shifted on the first capture after reset.
>> It doesn't matter whether I previous change the resolution with v4l2-ctl.
>> - On big images (1280 x 1024) the shift disappears after some images,
>> but not on small images (320 x 240).
>>
>> It looks like the FIFO was not cleared at start capture
> Sounds reasonable. Similar problem seen with ov7670 attached to pxa271.
> I've never taken the time to try and track it down.
>
I have fix the bug by moving the reset FIFO from
pxa_camera_start_capture to pxa_camera_irq
in front of the DMA activation after an end of frame interrupt.
I will send a patch tomorrow.
Regards,
Stefan
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-04-19 13:15 UTC | newest]
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2010-04-16 8:25 pxa_camera + ov9655: image shifted on first capture after reset Stefan Herbrechtsmeier
2010-04-16 10:07 ` Jonathan Cameron
2010-04-19 13:15 ` Stefan Herbrechtsmeier
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