SK-TDA4VM: Facing issue while detecting the second USB camera on SK-TDA4 evaluation hardware

Hi Prashant Shinde,

I really doubt we have validated USB based camera, i will check and confirm the same with Rahul Ravikumar. 

Since this is standard Linux USB driver, i would suggest to check this in Linux community. 

Regards,

Brijesh 

Hi Prashant Shinde,

Whatever printed on the terminal is from a helper script in edge_ai_apps
there was a small issue where it was parsing only on camera entry
you can apply below patch to edge_ai_apps to fix this
you 

From 9638a0592d6c2200cbfc8279c7a9b522b0d2ebfe Mon Sep 17 00:00:00 2001
From: Rahul T R <r-ravikumar@ti.com>
Date: Thu, 8 Sep 2022 12:05:41 +0530
Subject: [PATCH] setup: Add support to detect multiple USB cams

Currently only one USB camera gets detected,
Add support to detect multiple

Signed-off-by: Rahul T R <r-ravikumar@ti.com>
---
 scripts/setup_cameras.sh | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/scripts/setup_cameras.sh b/scripts/setup_cameras.sh
index 9ab59ad..f2830c7 100755
--- a/scripts/setup_cameras.sh
+++ b/scripts/setup_cameras.sh
@@ -145,10 +145,16 @@ setup_CSI_cameras(){
 }

 setup_USB_camera(){
-    USB_CAM_DEV=`ls /dev/v4l/by-path/*usb*video-index0 | head -1 | xargs readlink -f`
-    echo "USB Camera detected"
-    echo "    device = "$USB_CAM_DEV
-    echo "    format = jpeg"
+    USB_CAM_ARR=(`ls /dev/v4l/by-path/*usb*video-index0`)
+    count=0
+    for i in ${USB_CAM_ARR[@]}
+    do
+        USB_CAM_DEV=`readlink -f $i`
+        echo "USB Camera $count detected"
+        echo "    device = "$USB_CAM_DEV
+        echo "    format = jpeg"
+        count=$(($count + 1))
+    done
 }


--
2.37.2

Rahul T R

Hi Brijesh
Thanks for your input..

Hi Rahul Ravikumar...
Thanks you..

It looks need to change in the script file only.
So is there any change required in the Linux USB drive side?
Further if I connect both the USB camera sensor module to SK-TDA4 device , with this minimal change in the script that suggested by you , it will detect both the camera's and its drivers to get worked fine?

Hi Prashant Shinde,

Driver will load automatically
it just that the script was not printing

Also refer to below link to use two usb cams simultaneously
https://software-dl.ti.com/jacinto7/esd/processor-sdk-linux-sk-tda4vm/08_02_00/exports/docs/faq.html#getting-error-when-trying-to-capture-from-multiple-usb-cameras-simultaneously

Regards

Rahul T R

Hi Rahil 
Thanks for your input, I modified the script and tested over the SK-TDA4 board, now its detecting both the USB camera's.

PFA the snapshot for the same :

But one more thing I observed that , if I connected single camera to either of connector 1) USB device USB2.0 (Gen1) Type C  Or  2) USB3.1 (Gen1) Type A  

the device getting detected with video2 only. So that means USB driver itself detecting by default video2 device irrespective of the USB connector either 1) USB device USB2.0 (Gen1) Type C  Or  2) USB3.1 (Gen1) Type A  is it right?
 
Secondly can we connect 4 USB cameras with USB hub device and capture the images using all those?

Hi Prashant Shinde,

Yes you are correct, the enumeration is not based on what type of camera or USB port

Yes you can connect 4 cameras
please make the modification to the UVC driver as given in 
https://software-dl.ti.com/jacinto7/esd/processor-sdk-linux-sk-tda4vm/08_02_00/exports/docs/faq.html#getting-error-when-trying-to-capture-from-multiple-usb-cameras-simultaneously

Regards

Rahul T R

Hi Rahul,
Sorry for the late reply..

I gone through the link you shared, and referred all steps that mentioned in the page :
So using uvcvideo kernel patch for uvc usb device, made uvcvideo driver changes accordingly in the PSDK Linux and built driver to generate uvcvideo.ko file.Further tested the uvcvideo.ko file to validate uvc driver code patch changes by flashing it on SK HW. But after flashing uvcvideo.ko in SK hardware , I gone through below issue.

1) Once I given the last echo command: "echo 1200 > /sys/module/uvcvideo/parameters/bandwidth_cap"
It was showing an error "No such file or directory".PFA the snapshot for the same.

2) Even if we run the "init_script.sh" camera script , below observations I found 
- No USB getting detected. PFA the snapshot for the same.

3)Further while running SVS application for two camera's, it's not able to open the video devices, shows an error for both the USB camera's like
- "Can't open camera by index". PFA the snapshot for the same.

One more important observation I found that once I flash the "uvcvideo.ko" file in the SK hardware, and restart the hardware again
then at path "/sys/module/" , the uvcvideo folder is getting removed.

So with this experiment with the UVC driver , I came to conclusion that this driver patch may be for Jacinto board and not for SK-TDA4 board.
So could you please suggest the solution for these mentioned issue.

Note :I used "ti-processor-sdk-linux-j7-evm-08_04_00_11-Linux-x86-Install.bin" file for uvc driver changes.

Hi prashant shinde,

Can you please let me know, which version of SDK you used for
flashing the SD card,

You should use same version of PSDK Linux to apply the patch and build the .ko
file
If you share the EdgeAI SDK version, I can exactly point you to which PSDK LINUX to use

Regards

Rahul T R

Hi Rahul
I 'm using PSDK Linux : ti-processor-sdk-linux-j7-evm-08_04_00_11-Linux-x86-Install.bin installer with "08_04_00_11" this version.
And for flashing uvcvideo.ko , used sftp protocol application to flashed ".ko" file in the sd-card at path : rootfs\lib\modules\5.10.100-g7a7a3af903\kernel\drivers\media\usb\uvc. Could you please let me know is this driver patch for Jacinto board only ?

Hi Prashant,

You are using 8.2 SDK
please use 8.2 PSDK Linux to create .ko file

Below is the link for the same
PROCESSOR-SDK-LINUX-J721E Software development kit (SDK) | TI.com

Regards
Rahul T R

Hi Rahul
I generated separately uvcvideo.ko uvc kernel module on lower version 8.2 of PSDK Linux platform as well to validate UVCUSB kernel patch on SK-TDA4 EVM board and tested the camera setup script and svs application but even though observed the below same issues that shown in previous discussion:

- No USB getting detected.

- "Can't open camera by index"
So could you please suggest any different code change in UVC kernel patch which will solve this issue.

Hi Prasant,

Can you please share the boot logs
Also please try below command

insmod uvcvideo.ko

And send the output

Regards
Rahul T R