Update the vkms documentation to contain steps to:
- setup the vkms driver - run tests using igt
Signed-off-by: Sumera Priyadarsini sylphrenadin@gmail.com ___ Changes in v2: - Change heading to title case (Daniel) - Add examples to run tests directly (Daniel) - Add examples to run subtests (Melissa) --- Documentation/gpu/vkms.rst | 67 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+)
diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 13bab1d93bb3..d6739fbbe503 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -7,6 +7,73 @@ .. kernel-doc:: drivers/gpu/drm/vkms/vkms_drv.c :doc: vkms (Virtual Kernel Modesetting)
+Setup +===== + +The VKMS driver can be setup with the following steps: + +To check if VKMS is loaded, run:: + + lsmod | grep vkms + +This should list the VKMS driver. If no output is obtained, then +you need to enable and/or load the VKMS driver. +Ensure that the VKMS driver has been set as a loadable module in your +kernel config file. Do:: + + make nconfig + + Go to `Device Drivers> Graphics support` + + Enable `Virtual KMS (EXPERIMENTAL)` + +Compile and build the kernel for the changes to get reflected. +Now, to load the driver, use:: + + sudo modprobe vkms + +On running the lsmod command now, the VKMS driver will appear listed. +You can also observe the driver being loaded in the dmesg logs. + +To disable the driver, use :: + + sudo modprobe -r vkms + +Testing With IGT +================ + +The IGT GPU Tools is a test suite used specifically for debugging and +development of the DRM drivers. +The IGT Tools can be installed from +`here https://gitlab.freedesktop.org/drm/igt-gpu-tools`_ . + +The tests need to be run without a compositor, so you need to switch to text +only mode. You can do this by:: + + sudo systemctl isolate multi-user.target + +To return to graphical mode, do:: + + sudo systemctl isolate graphical.target + +Once you are in text only mode, you can run tests using the --device switch +or IGT_DEVICE variable to specify the device filter for the driver we want +to test:: + + sudo ./build/tests/<name of test> --device "sys:/sys/devices/platform/vkms" + sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/<name of test> + +For example, to test the functionality of the writeback library, +we can run the kms_writeback test:: + + sudo ./build/tests/kms_writeback --device "sys:/sys/devices/platform/vkms" + sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_writeback + +You can also run subtests if you do not want to run the entire test:: + + sudo ./build/tests/kms_flip --run-subtest basic-plain-flip --device "sys:/sys/devices/platform/vkms" + sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_flip --run-subtest basic-plain-flip + TODO ====