i.MX8MQ EVK HDMI outputs noises after the screen is captured

[james_wu]

Device: i.MX 8MQuad EVK rev B3

Software: L4.14.98_2.0.0_MX8MQ Linux Binary Demo Files

Use the Weston keyboard shortcut (SUPER + s) to capture the screenshot.

• Windows key and s key
• It's not easy to trigger this shortcut so please try it more

When the screen is captured, the captured screenshot (PNG format) is automatically stored in /wayland-screenshot-YYY-MM-DD_HH-mm-ss.png and the HDMI output becomes noisy.

The captured PNG file is correct. Please see the attached file, wayland-screenshot-2020-02-17_16-17-15.png.

There are a lot of noises on the HDMI output. Please see the attached photo, imx8mq-hdmi-output-noise.jpg.

Any solution/patch to solve this issue?

Thanks.

[james_wu]

This issue can be reproduced on L4.19.35_1.1.0_MX8MQ Linux Binary Demo Files.

[george]

Hi jameswu,

Now we are facing the exact same problem as you.

This problem does not occur with fbdev-backend, but seems to be a phenomenon specific to drm-backend.

If you have a clue to solving this problem, let us know.

Best Regards,

George

[james_wu]

Moving the USB mouse before pressing the (SUPER+s) shortcut will be easier to capture the screen.

[james_wu]

diegoadrian‌

The rate of occurrence for this issue is 100%.

[diegoadrian · Accepted solution]

Hello

This caused by DCSS, it handled the no compressed framebuffer as a compressed format. please try the attached patch.

Best regards,

Diego.

[james_wu]

Hi diegoadrian‌,

After I back port this patch to L4.14.98_2.0.0-GA, it works.

Thanks for helps.

BR,

James Wu

[diegoadrian]

Hello, 

I am reviewing this internally.

Best regards,

Diego.