Am 09.09.2019 um 10:40 schrieb Michael Mrozek EvilDragon@openpandora.org:

Isn't that a simple software rotation?

I have no idea what the differences are... That is why I am asking :)

If it is, it should be really slow.

Well, it may be a rotation feature of the text console driver. Some indication is that there is no "drm" in the /sys/class path.

For a console I would think speed does not matter much. But it may or may not use hardware rotation.

Looks as if we need someone who can explain the full software architecture in detail, i.e. every single step from user-space to display pixel and where which driver component is relevant...

BR, Nikolaus

On 9 September 2019 10:18:26 CEST, "H. Nikolaus Schaller" hns@goldelico.com wrote: Hi, I just learned that

root@letux:~# echo 0 > /sys/class/graphics/fbcon/rotate_all root@letux:~# echo 1 > /sys/class/graphics/fbcon/rotate_all root@letux:~# echo 2 > /sys/class/graphics/fbcon/rotate_all root@letux:~# echo 3 > /sys/class/graphics/fbcon/rotate_all

also does screen/framebuffer rotation.

Now I wonder why we need to patch drm_fb_helper (which is currently broken in letux-5.3) and have our own ./tiler-ctl script?

Any suggestions or explanations are welcome.

BR and thanks, Nikolaus Kernel mailing list Kernel@pyra-handheld.com http://pyra-handheld.com/cgi-bin/mailman/listinfo/kernel

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