[PATCH] drm: vc4: Don't wait for vblank when updating the cursor

[Michel Dänzer]

On 01/03/17 12:45 AM, Michael Zoran wrote:
> On Tue, 2017-02-28 at 16:42 +0900, Michel Dänzer wrote:
>> On 24/02/17 10:54 AM, Michael Zoran wrote:
>>> Commonly used desktop environments such as xfce4 and gnome
>>> on debian sid can flood the graphics drivers with cursor
>>> updates.
>>
>> FWIW, this has nothing to do with the desktop environment or indeed
>> the
>> client side at all. Translating input to HW cursor movement is
>> handled
>> entirely inside the X server.
>>
>>
> 
> Yes, as your point out it may well be the x server that is causing
> this.  I wasn't sure if it was the windows manager or the x server that
> was doing this.
> 
> Either way, when opening a new application the driver gets flooded with
> cursor updates as something is animating a spinning cursor.  Since the
> refresh rate is only 60Hz, I see a very long hang in the
> desktop(several minutes) where nothing responds.  SSHing into the RPI
> still works though even though it appears hung.
> 
> I had a few people on the net test the changes and they all report that
> without the change xfce4 and gnome are both unusable on the RPI.  With
> the change, things work fine.  Not waiting for the vblank on cursor
> updates is what other drivers appears to do as well...

Sure. My point is merely that the commit log should say "Xorg can flood
[...]" instead of "Commonly used desktop environments such as xfce4 and
gnome on debian sid can flood [...]".


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