[PATCH xserver 3/6] modesetting: add DRI2 page flip support

[Yu, Qiang]

>>> +    /* Post damage on the front buffer so that listeners, such
>>> +     * as DisplayLink know take a copy and shove it over the USB.
>>> +     * also for sw cursors.
>>> +     */
>>
>> SW cursors cannot work correctly with page flipping. For that reason,
>> xf86-video-ati/amdgpu disable page flipping while there's an SW cursor.
> [yuq] why? Is the problem in kernel or xserver?

The latter, due to the way SW cursor works. There's a fundamental (and
likely unfixable) conflict between the SW cursor and page flipping concepts.

[yuq] So the same problem for modesetting? I see no checking SW cursor
in original present page flip.

Regards,
Qiang