On Mon 28 Jun 20:07 CDT 2021, abhinavk@codeaurora.org wrote:
On 2021-06-28 17:55, Bjorn Andersson wrote:
On Mon 28 Jun 19:31 CDT 2021, abhinavk@codeaurora.org wrote:
Hi Bjorn
On 2021-06-28 17:22, Bjorn Andersson wrote:
The debugfs interface contains the knobs to make the DisplayPort controller output a test pattern, unfortunately there's nothing currently that actually enables the defined test pattern.
Fixes: de3ee25473ba ("drm/msm/dp: add debugfs nodes for video pattern tests") Signed-off-by: Bjorn Andersson bjorn.andersson@linaro.org
This is not how this debugfs node works. This is meant to be used while running DP compliance video pattern test.
https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/blob/master/tools/msm_dp_...
While the compliance test is being run with this msm_dp_compliance app running, it will draw the test pattern when it gets the "test_active" from the driver.
The test pattern which this app draws is as per the requirements of the compliance test as the test equipment will match the CRC of the pattern which is drawn.
The API dp_panel_tpg_config() which you are trying to call here draws the DP test pattern from the DP controller hardware but not the pattern which the compliance test expects.
So clearly not an oversight, but rather me not understanding how to use the test pattern.
You say that I should run msm_dp_compliance while the test is running, so how do I run the test?
There are two test patterns with different purposes. The one which the msm_dp_compliance draws is strictly for the DP compliance test and it needs even the DPU to draw the frame because it sets up the display pipeline and just draws the buffer.
That is not what you are looking for here.
So rather than trying to run msm_dp_compliance on your setup, just try calling dp_panel_tpg_config(). We typically just call this API, right after the link training is done. But if you really need a debugfs node for this, you can write up a separate debugfs for it Something like:
echo 1 > dp/tpg/en
Having the ability to turn on the test pattern was very useful to me and I would use this next time I'm adding DP support on a new platform. So adding some way of invoking that API without a lot of extra effort seems useful.
Lets not disturb this one.
Agreed.
Thanks, Bjorn
Its just a debug API to call when required during bringup/debug purposes.
Yes, I was trying to isolate the DP code from some misconfiguration in the DPU during bringup and with this fix the debugfs interface became useful.
Regards, Bjorn
Hence this is not the place to call it as it will end up breaking CTS.
Thanks
Abhinav
drivers/gpu/drm/msm/dp/dp_debug.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/msm/dp/dp_debug.c b/drivers/gpu/drm/msm/dp/dp_debug.c index 2f6247e80e9d..82911af44905 100644 --- a/drivers/gpu/drm/msm/dp/dp_debug.c +++ b/drivers/gpu/drm/msm/dp/dp_debug.c @@ -305,6 +305,8 @@ static ssize_t dp_test_active_write(struct file *file, debug->panel->video_test = true; else debug->panel->video_test = false;
dp_panel_tpg_config(debug->panel, debug->panel->video_test);