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Observer aclark
Observer
3,686 Views
Registered: ‎07-15-2013

XVDMA not being detected

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Hey guys,

 

Here is my error when loading the sobel demo application:

 

Cannot open device node xvdma
vdma_reset: Failed to get info for device id:0VDMA: XVDMA_STOP_TRANSFER calling failed
VDMA: XVDMA_DEVICE_CONTROL calling failed

 

 

A little background on my setup which shows this error:

 

* Custom kernel from tag 14.6.2 with enabled wifi and usb ethernet support 

* Using the device tree file from TRD 14.6

* Custom rootfs built via buildroot, using TRD 14.6's busybox and defconfig as a base

* 1920x1080 native resolution monitor.

 

My question is, I haven't done enough debugging to find out if it's my modified kernel or I missed something in buildroot, or I just simply have to generate a new device tree for my new kernel. At this stage, I'm using my ZC702 as merely a linux machine - no custom FPGA IP has been programmed or anything (as in, I opened the box and started messing with linux).

 

I will note, that when I use TRD 14.5 or 14.6, everything works fine. I just don't know enough about how to map these types of hardware interfaces to linux, and frankly, I can keep swapping out device tree files and kernels in a trial-and-error fashion, but I really want to understand what could be causing this. 

 

Oh, and I am "mounting" the interface as 14.6 / 14.5 do with: 

 

if [ ! -f /dev/xvdma ] ; then
    mknod /dev/xvdma c 10 224
fi

 

if [ ! -f /dev/xfilter ] ; then
    mknod /dev/xfilter c 10 235
fi

 

Again, I'd love some advice on where to ACTUALLY start debugging this. Thanks everyone!

 

-anthony

 

 

 

 

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Scholar rfs613
Scholar
4,611 Views
Registered: ‎05-28-2013

Re: XVDMA not being detected

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I'm afraid I haven't worked with the sobel demo, so I can only speculate.

This sounds like you're lacking a driver. The 14.6.2 tagged kernel may not include the necessary driver, or may simply not have it enabled. Check the kernel .config (which you can access via /proc/config.gz on a running system). Compare between your kernel, and the working one. Look for VDMA or FILTER in particular.

The device tree may also be a factor, as many drivers use parameters from the device tree to configure themselves. Again, I would recommend comparing the working TRD version to the one you are using.

-Ralph

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Scholar rfs613
Scholar
4,612 Views
Registered: ‎05-28-2013

Re: XVDMA not being detected

Jump to solution
I'm afraid I haven't worked with the sobel demo, so I can only speculate.

This sounds like you're lacking a driver. The 14.6.2 tagged kernel may not include the necessary driver, or may simply not have it enabled. Check the kernel .config (which you can access via /proc/config.gz on a running system). Compare between your kernel, and the working one. Look for VDMA or FILTER in particular.

The device tree may also be a factor, as many drivers use parameters from the device tree to configure themselves. Again, I would recommend comparing the working TRD version to the one you are using.

-Ralph

View solution in original post

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Observer aclark
Observer
3,646 Views
Registered: ‎07-15-2013

Re: XVDMA not being detected

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Thanks for the input. I've looked at the kernel configs and did some more trial-error with no avail. 

 

I guess the over-arching question is: What's the entire procedure for accessing the camera in a ZC702 imaging kit?  Or maybe there is some documentation in DocNav that I've missed. Any advice is appreciated!

 

-anthony

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Observer aclark
Observer
3,622 Views
Registered: ‎07-15-2013

Re: XVDMA not being detected

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Ah. So yes, I had the kernel drivers set incorrectly for XVDMA. I have that working and I can see the pipelines being probed in the boot log / dmesg. 

 

However, I am having XFILTER issues. I guess those might be from the devicetree and my `mknod` call not matching up.

Any ideas? I'll report back if I find anything. 

 

Also, I've been told by a Xilinx employee to look at XAPP794 for camera help. 

 

-anthony

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