Re: OMAP CCDC with sensors that are always on...

[Sakari Ailus <sakari.ailus@iki.fi>]

Hi Laurent,

Laurent Pinchart wrote:
> Hi Chris,
> 
> On Saturday 25 February 2012 01:48:02 Sakari Ailus wrote:
>> On Fri, Feb 17, 2012 at 05:32:31PM -0600, Chris Whittenburg wrote:
>>> I fixed my sensor to respect a "run" signal from the omap, so that now
>>> it only sends data when the ccdc is expecting it.
>>>
>>> This fixed my problem, and now I can capture the 640x1440 frames.
>>>
>>> At least the first one...
>>>
>>> Subsequent frames are always full of 0x55, like the ISP didn't write
>>> anything into them.
>>>
>>> I still get the VD0 interrupts, and I checked that WEN in the
>>> CCDC_SYN_MODE register is set, and that the EXWEN bit is clear.
>>>
>>> I'm using the command:
>>> yavta -c2 -p -F --skip 0 -f Y8 -s 640x1440 /dev/video2
>>>
>>> Here are my register settings:
>>>
>>> [ 6534.029907] omap3isp omap3isp: -------------CCDC Register
>>> dump------------- [ 6534.029907] omap3isp omap3isp: ###CCDC
>>> PCR=0x00000000
>>> [ 6534.029937] omap3isp omap3isp: ###CCDC SYN_MODE=0x00030f00
>>> [ 6534.029937] omap3isp omap3isp: ###CCDC HD_VD_WID=0x00000000
>>> [ 6534.029937] omap3isp omap3isp: ###CCDC PIX_LINES=0x00000000
>>> [ 6534.029968] omap3isp omap3isp: ###CCDC HORZ_INFO=0x0000027f
>>> [ 6534.029968] omap3isp omap3isp: ###CCDC VERT_START=0x00000000
>>> [ 6534.029968] omap3isp omap3isp: ###CCDC VERT_LINES=0x0000059f
>>> [ 6534.029998] omap3isp omap3isp: ###CCDC CULLING=0xffff00ff
>>> [ 6534.029998] omap3isp omap3isp: ###CCDC HSIZE_OFF=0x00000280
>>> [ 6534.029998] omap3isp omap3isp: ###CCDC SDOFST=0x00000000
>>> [ 6534.030029] omap3isp omap3isp: ###CCDC SDR_ADDR=0x00001000
>>> [ 6534.030029] omap3isp omap3isp: ###CCDC CLAMP=0x00000010
>>> [ 6534.030029] omap3isp omap3isp: ###CCDC DCSUB=0x00000000
>>> [ 6534.030059] omap3isp omap3isp: ###CCDC COLPTN=0xbb11bb11
>>> [ 6534.030059] omap3isp omap3isp: ###CCDC BLKCMP=0x00000000
>>> [ 6534.030059] omap3isp omap3isp: ###CCDC FPC=0x00000000
>>> [ 6534.030090] omap3isp omap3isp: ###CCDC FPC_ADDR=0x00000000
>>> [ 6534.030090] omap3isp omap3isp: ###CCDC VDINT=0x059e03c0
>>> [ 6534.030090] omap3isp omap3isp: ###CCDC ALAW=0x00000000
>>> [ 6534.030120] omap3isp omap3isp: ###CCDC REC656IF=0x00000000
>>> [ 6534.030120] omap3isp omap3isp: ###CCDC CFG=0x00008000
>>> [ 6534.030120] omap3isp omap3isp: ###CCDC FMTCFG=0x0000e000
>>> [ 6534.030151] omap3isp omap3isp: ###CCDC FMT_HORZ=0x00000280
>>> [ 6534.030151] omap3isp omap3isp: ###CCDC FMT_VERT=0x000005a0
>>> [ 6534.030151] omap3isp omap3isp: ###CCDC PRGEVEN0=0x00000000
>>> [ 6534.030181] omap3isp omap3isp: ###CCDC PRGEVEN1=0x00000000
>>> [ 6534.030181] omap3isp omap3isp: ###CCDC PRGODD0=0x00000000
>>> [ 6534.030181] omap3isp omap3isp: ###CCDC PRGODD1=0x00000000
>>> [ 6534.030212] omap3isp omap3isp: ###CCDC VP_OUT=0x0b3e2800
>>> [ 6534.030212] omap3isp omap3isp: ###CCDC LSC_CONFIG=0x00006600
>>> [ 6534.030212] omap3isp omap3isp: ###CCDC LSC_INITIAL=0x00000000
>>> [ 6534.030242] omap3isp omap3isp: ###CCDC LSC_TABLE_BASE=0x00000000
>>> [ 6534.030242] omap3isp omap3isp: ###CCDC LSC_TABLE_OFFSET=0x00000000
>>> [ 6534.030242] omap3isp omap3isp:
>>> --------------------------------------------
>>>
>>> Output frame 0 is always good, while output frame 1 is 0x5555.
>>>
>>> I believe my sensor is respecting the clocks required before and after
>>> the frame.
>>>
>>> Could the ISP driver be writing my data to some unexpected location
>>> rather than to the v4l2 buffer?
>>>
>>> Is there a way to determine if the CCDC is writing to memory or not?
>>
>> How long vertical blanking do you have? It shouldn't have an effect, though.
> 
> It definitely can :-) If vertical blanking isn't long enough, the CCDC will 
> start processing the next frame before the driver gets time to update the 
> hardware with the pointer to the next buffer. The first frame will then be 
> overwritten.

Sure, but in that case no buffers should be dequeued from the driver
either --- as they should always be marked faulty since reprogramming
the CCDC isn't possible.

Regards,

-- 
Sakari Ailus
sakari.ailus@iki.fi