Troubleshoot video

• Verify if the VPU driver is successfully loaded
• Verify if decoding/encoding is successfully offloaded to the VPU
• Debug the VPU driver, firmware, and GStreamer video plugins

Figure: Workflow to verify the VPU driver

1. Boot up the driver to begin the startup process and initialize the VPU driver.
2. Verify if the VPU driver is successfully loaded into the video system.
3. Verify if the video decoding and encoding tasks are appropriately handled by the VPU.
4. Run use cases to validate the VPU functionality.

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Verify if VPU driver is loaded on qcom-multimedia-proprietary-image

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Verify using the lsmod command

1. Run the lsmod command on the device shell:
   lsmod | grep -i "iris_vpu"
   
2. To verify that the VPU driver is loaded successfully, review the sample output and ensure that an entry for iris_vpu is available under the Module column:
   Module    Size    Used by
   iris_vpu   585728    0
   

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Verify using the udevadm command

1. Run the udevadm command on the device shell:
   udevadm info -n /dev/video*
   
2. To verify that the VPU is loaded successfully, review that the following sample output shows msm_vidc_decoder and msm_vidc_encoder against the ID_V4L_PRODUCT tag:
   P: /devices/platform/soc@0/aa00000.video-codec/video4linux/video32
   M: video32
   R: 32
   U: video4linux
   D: c 81:0
   N: video32
   L: 0
   S: v4l/by-path/platform-aa00000.video-codec-video-index0
   E: DEVPATH=/devices/platform/soc@0/aa00000.video-codec/video4linux/video32
   E: DEVNAME=/dev/video32
   E: MAJOR=81
   E: MINOR=0
   E: SUBSYSTEM=video4linux
   E: USEC_INITIALIZED=3749470
   E: ID_V4L_VERSION=2
   E: ID_V4L_PRODUCT=msm_vidc_decoder
   E: ID_V4L_CAPABILITIES=:
   E: ID_PATH=platform-aa00000.video-codec
   E: ID_PATH_TAG=platform-aa00000_video-codec
   E: ID_FOR_SEAT=video4linux-platform-aa00000_video-codec
   E: DEVLINKS=/dev/v4l/by-path/platform-aa00000.video-codec-video-index0
   E: TAGS=:seat:uaccess:
   E: CURRENT_TAGS=:seat:uaccess:
   |
   P: /devices/platform/soc@0/aa00000.video-codec/video4linux/video33
   M: video33
   R: 33
   U: video4linux
   D: c 81:1
   N: video33
   L: 0
   S: v4l/by-path/platform-aa00000.video-codec-video-index1
   E: DEVPATH=/devices/platform/soc@0/aa00000.video-codec/video4linux/video33
   E: DEVNAME=/dev/video33
   E: MAJOR=81
   E: MINOR=1
   E: SUBSYSTEM=video4linux
   E: USEC_INITIALIZED=3749498
   E: ID_V4L_VERSION=2
   E: ID_V4L_PRODUCT=msm_vidc_encoder
   E: ID_V4L_CAPABILITIES=:
   E: ID_PATH=platform-aa00000.video-codec
   E: ID_PATH_TAG=platform-aa00000_video-codec
   E: ID_FOR_SEAT=video4linux-platform-aa00000_video-codec
   E: DEVLINKS=/dev/v4l/by-path/platform-aa00000.video-codec-video-index1
   E: TAGS=:seat:uaccess:
   E: CURRENT_TAGS=:seat:uaccess:
   

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Verify if VPU driver is loaded on qcom-multimedia-image

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Verify using the lsmod command

1. Run the following lsmod command on the device shell for Dragonwing IQ-8275, Dragonwing IQ-9075, QCS6490:
   lsmod | grep -i "qcom_iris"
   
2. To verify that the VPU driver is loaded successfully, review the sample output and ensure that an entry for qcom_iris is available under the Module column:
   Module    Size    Used by
   qcom_iris   585728    0
   
3. Run the following lsmod command on the device shell for QCS615:
   lsmod | grep -i "venus"
   
4. To verify that the VPU driver is loaded successfully, review the sample output and ensure that an entry for venus is available under the Module column:
   Module    Size    Used by
   venus_enc   28672    0
   venus_dec   28672    0
   

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Verify using the udevadm command

1. Run the udevadm command on the device shell:
   udevadm info -a -n /dev/video*
   

   Note:

   Run the udevadm info -a -n /dev/video<0 to 27> command on all available video nodes.

2. To verify that the VPU is loaded successfully for Dragonwing IQ-8275/Dragonwing IQ-9075/ QCS6490, review that the sample output shows qcom-iris-decoder and qcom-iris-encoder against available video devices:

   '/devices/platform/soc@0/aa00000.video-codec/video4linux/video0':
   KERNEL=="video0"
   SUBSYSTEM=="video4linux"
   DRIVER==""
   ATTR{dev_debug}=="0"
   ATTR{index}=="0"
   ATTR{name}=="qcom-iris-decoder"
   ATTR{power/control}=="auto"
   ATTR{power/runtime_active_time}=="0"
   ATTR{power/runtime_status}=="unsupported"
   ATTR{power/runtime_suspended_time}=="0"
   

3. To verify that the VPU is loaded successfully for QCS615, review that the sample output shows qcom-venus-decoder and qcom-venus-encoder against available video devices:

   '/devices/platform/soc@0/aa00000.video-codec/video4linux/video0':
   KERNEL=="video0"
   SUBSYSTEM=="video4linux"
   DRIVER==""
   ATTR{dev_debug}=="0"
   ATTR{index}=="0"
   ATTR{name}=="qcom-venus-decoder"
   ATTR{power/control}=="auto"
   ATTR{power/runtime_active_time}=="0"
   ATTR{power/runtime_status}=="unsupported"
   ATTR{power/runtime_suspended_time}=="0"
   

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Verify if decoding and encoding are offloaded on qcom-multimedia-proprietary-image

1. Run the following command in a loop:

cat /proc/interrupts | grep "msm-vidc"

Sample output:

253: 4        0        0        0        0        0        0        0     GICv3 206 Level  msm-vidc

2. Verify that the interrupt count from msm-vidc increases on any CPU while the decoding or encoding use case is running.

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Verify if decoding/encoding is offloaded on qcom-multimedia-image

1. Run the following command in a loop for Dragonwing IQ-8275/Dragonwing IQ-9075/QCS6490:

cat /proc/interrupts | grep "iris"

Sample output:

253: 4        0        0        0        0        0        0        0     GICv3 206 Level  iris

2. Verify that the interrupt count from iris increases on any CPU while the decoding or encoding use case is running.
3. Run the following command in a loop for QCS615:

cat /proc/interrupts | grep "venus"

Sample output:

253: 4        0        0        0        0        0        0        0     GICv3 206 Level  venus

4. Verify that the interrupt count from venus increases on any CPU while the decoding or encoding use case is running.

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Debug video

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Debug the VPU driver

Figure: Debug VPU workflow

1. Mount the debug file system to start the debug process.
2. Choose the preferred log level.
3. Configure the log levels for the VPU driver and/or the firmware as needed.
4. Apply the chosen log level using the debugfs node.
5. Start capturing logs for both the VPU driver and the firmware.

1. Mount the debugfs node using the following command:
   mount -t debugfs none /sys/kernel/debug/
   
2. Choose the VPU driver debug log level and debug log value as listed in the following table. You can also select multiple debug log levels by using the bitmask of debug log values.

3. Set the VPU driver debug log value to the /sys/module/iris_vpu/parameters/msm_vidc_debug node. The sample command to activate all message levels:
   echo 0x1000037F > /sys/module/iris_vpu/parameters/msm_vidc_debug
   
4. Choose the VPU firmware debug log level and debug log value as listed in the following table. You can also select many debug log levels by using the bitmask of debug log values.

5. Set the VPU firmware debug log value to the /sys/module/iris_vpu/parameters/msm_fw_debug node. Sample command to activate all message levels:
   echo 0x1000037F > /sys/module/iris_vpu/parameters/msm_fw_debug
   
6. Start capturing kernel messages for both the VPU driver and the firmware using the following command in device shell and run the use case:
   cat /proc/kmsg or dmesg -w
   

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Debug the GStreamer plugins