drm: simpledrm: fbdev emulation error with CONFIG_DRM_SIMPLEDRM enabled

[Thomas Zimmermann]

Hi Amanoel

Am 25.08.21 um 21:12 schrieb Amanoel Dawod:
> 
> No problem, managed to boot directly into a text terminal and grabbed DRM
> related dmesg log.
> Hopefully it's what you're looking for :)
> 
> Find it attached please.

Thanks, this was helpful. The failure is shown at

> [    3.263394] [drm:0xffffffffc0303583] bad framebuffer height 2304, should be >= 768 && <= 768

where the FB height is too large. But I'm puzzled why this happens. The 
only way seems to be tiling, which isn't supported by Linux' simple 
framebuffers AFAIK. All framebuffers are supposed to be linear.

You said that the resolution is 3840 x 2160, but the attached log says 
1024x768. I guess that the former is the monitor's native resolution and 
the latter is the display mode?

The attached patch adds a few extra lines of debugging output. Could you 
please apply it, rebuild, and report back with the log.

Best regards
Thomas

> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
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