# Debug This information provides the necessary details to troubleshoot and analyze various components, such as the DSI panel clock, DPU, and Weston. Tab QCS6490/QCS5430 Tab QCS9075/QCS8275 - *class* tabincludedirective - ## Display panel and clock > > > Note > > > - You must enable SSH to access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). > - To mount the `debugfs` file system to access the `debugfs` details of the display subsystem, run the following commands: > > > > > > > > > mount -o remount,rw / > > Copy to clipboard > > > > > > mount -t debugfs none /sys/kernel/debug > > Copy to clipboard **View display panel information** To check the selected display panel, run the following command: cat /sys/kernel/debug/qcom,mdss_dsi_ext_bridge_rb3gen2/dump_info Copy to clipboard **Sample output** name = qcom,mdss_dsi_ext_bridge_rb3gen2 Resolution = 1920(148|88|44|1)x1080(36|4|5|1)@60fps 0 Hz CTRL_0: ctrl = dsi-ctrl-0 phy = dsi-phy-0 Panel = ext video mode dsi bridge Clock master = dsi-ctrl-0 Copy to clipboard **View DSI clock information** To check the DSI clock information, run the following command: > > > cat /sys/kernel/debug/qcom,mdss_dsi_ext_bridge_rb3gen2/dsi-ctrl-0/state_info > Copy to clipboard **Sample output** > > > Current State: > CTRL_ENGINE = ON > VIDEO_ENGINE = ON > COMMAND_ENGINE = OFF > Clock Info: > BYTE_CLK = 111375000, PIXEL_CLK = 148500000, ESC_CLK = 19200000 > Copy to clipboard ## Check regulator information To check the regulator status and the voltage, run the following command: cat /sys/kernel/debug/regulator/regulator_summary Copy to clipboard ## Display interface information To retrieve the debug dump output (display interface number, VSync count, underrun count, and interface modes), run the following command: cat /sys/kernel/debug/dri/0/encoder*/status Copy to clipboard **Sample output** intf:1 vsync: 192124 underrun: 0 mode: video Copy to clipboard ## SDE layer mixers and layer information The Snapdragon display engine (SDE) layer mixer information is available to licensed developers with authorized access. For more information, see [Qualcomm Linux Display Guide - Addendum](https://docs.qualcomm.com/bundle/resource/topics/80-70017-18A/debug.html). ## General DPU debugging information The common DPU debugging information is provided as follows: > > > **DPU clock rate** > > > Note > > > You must enable SSH to access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). > > > To check the DPU clock rate, run the following command: > > > > > > > > > cat /sys/kernel/debug/clk/clk_summary | grep disp_cc > > Copy to clipboard > > > > **Set DPU to Performance mode** > > > To set the DPU to Performance mode, run the following commands: > > > > > > > > > cd /sys/kernel/debug/dri/0/debug/core_perf/ > > Copy to clipboard > > > > > > echo 1 > perf_mode > > Copy to clipboard ## User mode/Weston debug ### Weston autolaunch The Weston screen automatically launches when the device is powered on. The `/etc/initscripts/init_qti_display` script file contains the Weston configurations and the corresponding command-line parameters that have been used to set up the Weston screen autolaunch. Note You must enable SSH to access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). mount -o remount,rw / Copy to clipboard cat /etc/initscripts/init_qti_display Copy to clipboard ### Weston display configuration Weston uses the `weston.ini` configuration file. When Weston starts, it searches for the `weston.ini` file from the Weston init script as `--config=/etc/xdg/weston/weston.ini` and configures the Weston display pipeline. The detailed configurations are described at [https://manpages.ubuntu.com/manpages/focal/en/man5/weston.ini.5.html](https://manpages.ubuntu.com/manpages/focal/en/man5/weston.ini.5.html). To fetch the Weston configuration file, run the following commands: mount -o remount,rw / Copy to clipboard cat /etc/xdg/weston/weston.ini Copy to clipboard After executing the commands, you see the following `weston.ini` configuration sample output: configuration file for Weston [core] idle-time=0 backend=sdm-backend.so repaint-window=10 [output] name=DSI-1 mode=on [output] name=DP-1 mode=on [shell] clock-format=seconds Copy to clipboard ### Relaunch Weston To kill the Weston process and manually relaunch the Weston server, do the following: Note You must enable SSH to access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). 1. To identify the ID of the Weston processes, run the following commands: > > > mount -o remount,rw / > Copy to clipboard > > > ps -A | grep weston > Copy to clipboard > > > **Sample output** > > > 824 ? 00:00:12 weston > 1090 ? 00:00:00 weston-keyboard > 1092 ? 00:00:01 weston-desktop- > Copy to clipboard 2. To kill the Weston process, run the following command: > > > killall weston > Copy to clipboard 3. To relaunch the Weston server, run the following commands: > > > mount -o remount,rw / > Copy to clipboard > > > su > Copy to clipboard > > > . /etc/profile > Copy to clipboard > > > export XDG_RUNTIME_DIR=/dev/socket/weston > Copy to clipboard > > > mkdir --parents $XDG_RUNTIME_DIR > Copy to clipboard > > > chmod 0700 $XDG_RUNTIME_DIR > Copy to clipboard > > > cd /usr/bin > Copy to clipboard > > > ./weston --tty=2 --continue-without-input > Copy to clipboard ## HDMI troubleshooting LT9611uxc is the DSI-to-HDMI bridge chip firmware. The recommended firmware version is `LT9611UXC_DSI_PortA_HDCP_Disable_V5.0.21.bin`. If you experience a no-display screen on the HDMI, it is recommended to upgrade the firmware. **Upgrade Lontium firmware** To upgrade the Lontium firmware, do the following: 1. Download the recommended LT9611uxc firmware version `LT9611UXC_DSI_PortA_HDCP_Disable_V5.0.21.bin` from [http://www.lontiumsemi.com/download](http://www.lontiumsemi.com/download) and go to the Qualcomm section. > > > Note > > - Enable SSH to access your host device. For more information, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). > - When prompted for a password, enter oelinux123. 2. To upgrade the firmware, run the following Linux shell commands: > > > mount -o rw,remount / > Copy to clipboard > > > scp root@:/lib/firmware/lt9611uxc_fw.bin > Copy to clipboard > > > sync > Copy to clipboard > > > echo 0 > /sys/bus/i2c/devices/0-002b/lt9611uxc_firmware > Copy to clipboard > > > Note > > > Wait for at least 3 minutes for the firmware upgrade to complete. 3. To retrieve the lt9611 logs, run the following command: > > > dmesg | grep lt9611 > Copy to clipboard The `Firmware updates successfully` log confirms that the firmware upgrade is successful. To ensure that the new firmware is in effect, it is recommended to hard reboot (unplug and plug in the power cable) the device. - *class* tabincludedirective - ## DisplayPort panel and clock > > > Note > > - You must enable SSH to access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). > - To mount the `debugfs` file system to access the `debugfs` details of the display subsystem, run the following commands: > > > > > > > > > mount -o remount,rw / > > Copy to clipboard > > > > > > mount -t debugfs none /sys/kernel/debug > > Copy to clipboard **View DisplayPort panel information** To check the selected DisplayPort panel, run the following command: cat /sys/kernel/debug/dri/0/msm_dp-DP-1/dp_debug Copy to clipboard **Sample output** name = msm_dp drm_dp_link rate = 270000 num_lanes = 4 capabilities = 1 dp_panel_info: active = 3840x2160 back_porch = 80x23 front_porch = 48x3 sync_width = 32x5 active_low = 0x0 h_skew = 0 refresh rate = 30 pixel clock khz = 262750 bpp = 30 dp_link: test_requested = 512 num_lanes = 4 bw_code = 10 lclk = 270000000 v_level = 1 p_level = 0 Copy to clipboard **View status of DisplayPort cable** To check if the DisplayPort cable is connected, run the following command: cat /sys/class/drm/card0-DP-1/status Copy to clipboard **Sample output** Connected Copy to clipboard **Check EDID mode** To check for the EDID mode of the DisplayPort panel connected, run the following command: cat /sys/class/drm/card0-DP-1/modes Copy to clipboard **Sample output** 3840x2160 2048x1080 1920x1080 1280x720 Copy to clipboard ## Check regulator information To check the regulator status and the voltage, run the following command: cat /sys/kernel/debug/regulator/regulator_summary Copy to clipboard ## Display interface information The following are the debug dump-outs: Display interface number, VSync count, underrun count, and interface modes. cat /sys/kernel/debug/dri/0/encoder*/status Copy to clipboard **Sample output** intf:1 vsync: 192124 underrun: 0 mode: video Copy to clipboard ## Snapdragon Display Engine (SDE) layer mixers and layer information The SDE layer mixer information is currently available for users with full access to the proprietary software shipped with Qualcomm Linux. For more information, see [Qualcomm Linux Display Guide - Addendum](https://docs.qualcomm.com/bundle/resource/topics/80-70017-18A/debug.html) ## General DPU debugging information The common DPU debugging information is provided as follows: > > > **DPU clock rate** > > > Note > > > You must enable SSH to securely access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). > > > To check the DPU clock rate, run the following commands: > > > cat /sys/kernel/debug/clk/clk_summary | grep disp_cc > Copy to clipboard > > > **Set DPU to Performance mode** > > > To set the DPU to Performance mode, run the following commands: > > > cd /sys/kernel/debug/dri/0/debug/core_perf/ > Copy to clipboard > > > echo 1 > perf_mode > Copy to clipboard ## User mode/Weston debug ### Weston autolaunch The Weston screen automatically launches when you power on the device. The `/etc/initscripts/init_qti_display` script file contains the Weston configurations and the corresponding command-line parameters that are used to set up the Weston screen autolaunch. Note You must enable SSH to access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). mount -o remount,rw / Copy to clipboard cat /etc/initscripts/init_qti_display Copy to clipboard ### Relaunch Weston To kill the Weston process and manually relaunch the Weston server, do the following: > > > Note > > > You must enable SSH to access your host device. For instructions, see [Use SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70017-254/how_to.html#use-ssh). 1. To identify the ID of the Weston processes, run the following commands: > > > mount -o remount,rw / > Copy to clipboard > > > ps -A | grep weston > Copy to clipboard > > > **Sample output** > > > 824 ? 00:00:12 weston > 1090 ? 00:00:00 weston-keyboard > 1092 ? 00:00:01 weston-desktop- > Copy to clipboard 2. To kill the Weston process, run the following command: > > > killall weston > Copy to clipboard 3. To relaunch the Weston server, run the following commands: > > > mount -o remount,rw / > Copy to clipboard > > > su > Copy to clipboard > > > . /etc/profile > Copy to clipboard > > > export XDG_RUNTIME_DIR=/dev/socket/weston > Copy to clipboard > > > mkdir --parents $XDG_RUNTIME_DIR > Copy to clipboard > > > chmod 0700 $XDG_RUNTIME_DIR > Copy to clipboard > > > cd /usr/bin > Copy to clipboard > > > ./weston --tty=2 --continue-without-input > Copy to clipboard Last Published: Dec 19, 2024 [Previous Topic Configure](https://docs.qualcomm.com/bundle/publicresource/80-70017-18/topics/configure.md) [Next Topic References](https://docs.qualcomm.com/bundle/publicresource/80-70017-18/topics/references.md)