HDMI doesn't refresh - IMX8mp

[ZhouLiang1]

Hi, experts

I recently encountered an HDMI display problem. During the test, I test HDMI display with weston service. Sometimes the HDMI screen could not be refreshed, but the pictures in weston's memory had been updated(I have dumped the memory into png files). Please tell me how to check the HDMI's registers to find out the problem?

I check the lcdif3 register, and find when  HDMI does refresh, the register of lcdif has a little difference:

0x32fc6024 = 01000003

From the iMX process manual we can know the UNDERRUN flag is being set.

Thank you

Best Regards

Snow

[joanxie]

what kind of testing cause such issue? pls share more detailed information, how to reproduce this  and what bsp version do you use?

[ZhouLiang1]

Hi, joanxie

I used mainline linux for testing before, not linux-imx. The test steps are:

plug and unplug HDMI cable

During this test process, there is a certain probability that this problem will occur.

Although I am using mainLine linux, I still want to know what causes the FIFO empty error in lcdif

Thank you!

[joanxie]

could you share your detailed error message? how do you get these errors, just hot plug the hdmi? pls share more detailed information

[joanxie]

i.mx8mp has known issue about The weston stuck because of drm atomic fail after hotplug. the internal team is still work on this issue

[ZhouLiang1]

In your known issue description,  are there also FIFO empty and UNDER RUN exceptions according to the register value?

Can you provide more information about your know issue?

Thank you.