On 24/08/11 21:12, Laurent Pinchart wrote:

On Wednesday 24 August 2011 03:17:39 CJ wrote:

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On 23/08/11 19:47, Laurent Pinchart wrote:

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On Tuesday 23 August 2011 05:47:20 CJ wrote:

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On 22/08/11 22:15, Michael Jones wrote:

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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.

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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