Re: [beagleboard] Re: [PATCH v7 1/2] Add driver for Aptina (Micron) mt9p031 sensor.

[CJ <cjpostor@gmail.com>]

On 24/08/11 21:12, Laurent Pinchart wrote:
> On Wednesday 24 August 2011 03:17:39 CJ wrote:
>> On 23/08/11 19:47, Laurent Pinchart wrote:
>>> On Tuesday 23 August 2011 05:47:20 CJ wrote:
>>>> On 22/08/11 22:15, Michael Jones wrote:
>>>>>>>>> I am trying to get the mt9p031 working from nand with a ubifs file
>>>>>>>>> system and I am having a few problems.
>>>>>>>>>
>>>>>>>>> /dev/media0 is not present unless I run:
>>>>>>>>> #mknod /dev/media0 c 251 0
>>>>>>>>> #chown root:video /dev/media0
>>>>>>>>>
>>>>>>>>> #media-ctl -p
>>>>>>>>> Enumerating entities
>>>>>>>>> media_open: Unable to enumerate entities for device /dev/media0
>>>>>>>>> (Inappropriate ioctl for device)
>>>>>>>>>
>>>>>>>>> With the same rig/files it works fine running from EXT4 on an SD
>>>>>>>>> card. Any idea why this does not work on nand with ubifs?
>>>>>>>> Is the OMAP3 ISP driver loaded ? Has it probed the device
>>>>>>>> successfully ? Check the kernel log for OMAP3 ISP-related messages.
>>>>>>> Here is the version running from SD card:
>>>>>>> # dmesg | grep isp
>>>>>>> [    0.265502] omap-iommu omap-iommu.0: isp registered
>>>>>>> [    2.986541] omap3isp omap3isp: Revision 2.0 found
>>>>>>> [    2.991577] omap-iommu omap-iommu.0: isp: version 1.1
>>>>>>> [    2.997406] omap3isp omap3isp: hist: DMA channel = 0
>>>>>>> [    3.006256] omap3isp omap3isp: isp_set_xclk(): cam_xclka set to
>>>>>>> 21600000 Hz
>>>>>>> [    3.011932] omap3isp omap3isp: isp_set_xclk(): cam_xclka set to 0
>>>>>>> Hz
>>>>>>>
>>>>>>>     From NAND using UBIFS:
>>>>>>> # dmesg | grep isp
>>>>>>> [    3.457061] omap3isp omap3isp: Revision 2.0 found
>>>>>>> [    3.462036] omap-iommu omap-iommu.0: isp: version 1.1
>>>>>>> [    3.467620] omap3isp omap3isp: hist: DMA channel = 0
>>>>>>> [    3.472564] omap3isp omap3isp: isp_set_xclk(): cam_xclka set to
>>>>>>> 21600000 Hz
>>>>>>> [    3.478027] omap3isp omap3isp: isp_set_xclk(): cam_xclka set to 0
>>>>>>> Hz
>>>>>>>
>>>>>>> Seems to be missing:
>>>>>>> omap-iommu omap-iommu.0: isp registered
>>>>>>>
>>>>>>> Is that the issue? Why would this not work when running from NAND?
>>>>> I'm not sure, either, but I had a similar problem before using
>>>>> Laurent's patch below. IIRC, usually udev would create /dev/media0
>>>>> from a cached list of /dev/*. Later modutils would come along and load
>>>>> the modules in the proper order (iommu, then omap3-isp) and everybody
>>>>> was happy. Occasionally, udev would fail to use the cached version of
>>>>> /dev/, and look through /sys/devices to re-create the devices in
>>>>> /dev/. When media0 was found, omap3-isp.ko would be loaded, but iommu
>>>>> had not yet been, presumably because it doesn't have an entry in
>>>>> /sys/devices/. So maybe udev is behaving differently for you on NAND
>>>>> than it did on the card? Either way, as I said, using Laurent's patch
>>>>> below did the job for me.
>>>>>
>>>>>> I'm not sure why it doesn't work from NAND, but the iommu2 module
>>>>>> needs to be loaded before the omap3-isp module. Alternatively you can
>>>>>> compile the iommu2 module in the kernel with
>>>>>>
>>>>>> diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
>>>>>> index 49a4c75..3c87644 100644
>>>>>> --- a/arch/arm/plat-omap/Kconfig
>>>>>> +++ b/arch/arm/plat-omap/Kconfig
>>>>>> @@ -132,7 +132,7 @@ config OMAP_MBOX_KFIFO_SIZE
>>>>>>
>>>>>>     	  module parameter).
>>>>>>
>>>>>>     config OMAP_IOMMU
>>>>>>
>>>>>> -       tristate
>>>>>> +       bool
>>>>>>
>>>>>>     config OMAP_IOMMU_DEBUG
>>>>>>
>>>>>>            tristate "Export OMAP IOMMU internals in DebugFS"
>>>> Thanks for the help!
>>>>
>>>> For some reason dmesg does not read early kernel stuff when in UBIFS
>>>> from NAND.
>>>> So when I went back and had a look the line I thought was not there is
>>>> actually included.
>>>>
>>>> [    0.276977] omap-iommu omap-iommu.0: isp registered
>>>>
>>>> So I guess everything is loading fine.
>>>>
>>>> I tried the patch and it didn't make a difference.
>>>>
>>>> Regarding what Michael said /dev/media0 is not created by udev when boot
>>>> from NAND.
>>>> I tried creating it manually with:
>>>> #mknod /dev/media0 c 251 0
>>>> #chown root:video /dev/media0
>>>>
>>>> But this does not work - outputs:
>>>>
>>>> # media-ctl -r -l '"mt9p031 2-0048":0->"OMAP3 ISP CCDC":0[1], "OMAP3 ISP
>>>> CCDC":2->"OMAP3 ISP preview":0[1], "OMAP3 ISP preview":1->"OMAP3 ISP
>>>> resizer":0[1], "OMAP3 ISP resizer":1->"OMAP3 ISP resizer output":0[1]'
>>>> media_open: Unable to enumerate entities for device /dev/media0
>>>> (Inappropriate ioctl for device)
>>>>
>>>> So is there a problem with udev?
>>> There could be. What's the output of
>>>
>>> ls /sys/class/video4linux
>> #ls /sys/class/video4linux
>> v4l-subdev0  v4l-subdev3  v4l-subdev6  video0       video3       video6
>> v4l-subdev1  v4l-subdev4  v4l-subdev7  video1       video4
>> v4l-subdev2  v4l-subdev5  v4l-subdev8  video2       video5
> Devices are correctly registered with the Linux kernel. Does 'ls /dev/v4l-
> subdev*' show the same entries ? If not you probably have a udev issue.
>

Slightly different..

# ls /dev/v4l-subdev*
/dev/v4l-subdev0  /dev/v4l-subdev3  /dev/v4l-subdev6
/dev/v4l-subdev1  /dev/v4l-subdev4  /dev/v4l-subdev7
/dev/v4l-subdev2  /dev/v4l-subdev5  /dev/v4l-subdev8

I probably should have said this earlier .. but I am using mdev not udev.
It does work fine with exactly the same system running from the card in 
EXT4.

Any other thoughts?

Cheers,
Chris