[PATCH v3] drm/vkms: Add setup and testing information

[Melissa Wen]

On 12/09, Daniel Vetter wrote:
> On Thu, Dec 10, 2020 at 12:34:53AM +0530, Sumera Priyadarsini wrote:
> > Update the vkms documentation to contain steps to:
> > 
> >  - setup the vkms driver
> >  - run tests using igt
> > 
> > Signed-off-by: Sumera Priyadarsini <sylphrenadin at gmail.com>
> > ___
> > Changes in v2:
> >  - Change heading to title case (Daniel)
> >  - Add examples to run tests directly (Daniel)
> >  - Add examples to run subtests (Melissa)
> > 
> > Changes in v3:
> >  - Add example using run-tests.sh script(Daniel)
> 
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
Applied to drm-misc-next.

Thanks for these improvements,

Melissa
> > ---
> >  Documentation/gpu/vkms.rst | 70 ++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 70 insertions(+)
> > 
> > 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
> >  ====
> >  
> > -- 
> > 2.25.1
> > 
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch