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From: Stefan Herbrechtsmeier <hbmeier@hni.uni-paderborn.de>
To: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
	Linux Media Mailing List <linux-media@vger.kernel.org>
Subject: Re: pxa_camera + ov9655: image shifted on first capture after reset
Date: Mon, 19 Apr 2010 15:15:39 +0200	[thread overview]
Message-ID: <4BCC577B.1090905@hni.uni-paderborn.de> (raw)
In-Reply-To: <4BC836FD.8010301@cam.ac.uk>

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

      reply	other threads:[~2010-04-19 13:15 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
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 [this message]

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