[PATCH xserver 1/2] modesetting: Fix reverse prime partial update issues on secondary GPU outputs

[Michel Dänzer]

On 16/09/16 06:50 AM, Eric Anholt wrote:
> Hans de Goede <hdegoede at redhat.com> writes:
> 
>> When using reverse prime we do 2 copies, 1 from the primary GPU's
>> framebuffer to a shared pixmap and 1 from the shared pixmap to the
>> secondary GPU's framebuffer.
>>
>> This means that on the primary GPU side the copy MUST be finished,
>> before we start the second copy (before the secondary GPU's driver
>> starts processing the damage on the shared pixmap).
>>
>> This fixes secondary outputs sometimes showning (some) old fb contents,
>> because of the 2 copies racing with each other, for an example of
>> what this looks like see:
> 
> Is working around the fact that the primary and secondary aren't
> cooperating on dmabuf fencing?  Should they be doing that instead?
> 
> Or would glamor_flush be sufficient?

Yes, glamor_flush is sufficient if the kernel drivers handle fences
correctly.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 163 bytes
Desc: OpenPGP digital signature
URL: <https://lists.x.org/archives/xorg-devel/attachments/20160916/c8a40804/attachment.sig>