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Diffstat (limited to 'Documentation/gpu/vkms.rst')
| -rw-r--r-- | Documentation/gpu/vkms.rst | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 13bab1d93bb3..9e030c74a82e 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -7,6 +7,76 @@ .. 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. IGT_DEVICE can also be used with the run-test.sh script to run the +tests for a specific driver:: + + 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> + sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t <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 + sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./scripts/run-tests.sh -t 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 ==== |