On Thu, Mar 31, 2022 at 08:13:09PM +0800, Andy Yan wrote:

Hi Piotr:

On 3/31/22 03:20, Sascha Hauer wrote:

quoted

On Wed, Mar 30, 2022 at 04:52:22PM +0200, Piotr Oniszczuk wrote:

quoted

quoted

Wiadomość napisana przez Sascha Hauer [off-list ref] w dniu 30.03.2022, o godz. 12:20:

Does it change anything if you do a "modetest -s 69@67:1920x1080" before
starting the app? Or if you run "modetest -P 43@67:1920x1080@NV12"
before starting the app? Or other combinations thereof?

So i tried following combinations

-boot
-modetest -s 69@67:1920x1080 -> ok
-modetest -P 43@67:1920x1080@NV12 -> green screen

I have no idea what is going on here. There same commands work for me.
You could provide me your kernel config and upstream commitish you are
working on, maybe that gets me closer to your setup.

It's a little strange, I can't reproduce this issue neither.

But I have problem with this two step command sequence.

step 1:  modetest -s 69@67:1920x1080 -> ok

step 2:  modetest -P 43@67:1920x1080@NV12,

I got the failed message:  "failed to enable plane: Permission denied"

Because the drm core will stop step2 by drm_ioctrl_permit as
DRM_IOCTL_SETPLANE need a master,

but the current master is the modetest run by step1.

[...]

So how you two got step two run success?

You have to stop the first modetest by hitting return. Alternatively you
could pass the -d option to the first modetest.

Sascha

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