[PATCH 0/6] drm: Add mouse cursor hotspot support to atomic KMS

Simon Ser contact at emersion.fr
Fri Jun 10 08:54:03 UTC 2022

I agree with what others have replied, just adding a few more details.

On Thursday, June 9th, 2022 at 21:39, Zack Rusin <zackr at vmware.com> wrote:

> virtualized drivers send drm_kms_helper_hotplug_event which sends a HOTPLUG=1
> event with a changed preferred width/height

(Note: and the "hotplug_mode_update" property is set to 1.)

> suggested_x and suggested_y properties

These come with their own set of issues. They are poorly defined, but it seems
like they describe a position in physical pixel coordinates. Compositors don't
use physical pixel coordinates to organize their outputs, instead they use
logical coordinates. For instance, a HiDPI 4k screen with a scale of 2 will
take up 1920x1080 logical pixels. There is no way to convert physical pixel
coordinates to logical pixel coordinates in the general case, because there's
no "global scale factor". So suggested_x/y are incompatible with the way
compositors work.

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