[PATCH 1/2] drm/amdgpu: Enable scatter gather display support

[Li, Samuel]

> Buffer placement is specified by the DDX/Mesa, when we override that in the kernel we just force unnecessary buffer moves.
Since scan out buffer is moved to GTT now, DDX/Mesa might need to make some changes for this too.

Regards,
Samuel Li


> -----Original Message-----
> From: Christian König [mailto:ckoenig.leichtzumerken at gmail.com]
> Sent: Tuesday, March 06, 2018 1:02 PM
> To: Michel Dänzer <michel at daenzer.net>; Koenig, Christian
> <Christian.Koenig at amd.com>; Li, Samuel <Samuel.Li at amd.com>; Alex
> Deucher <alexdeucher at gmail.com>
> Cc: amd-gfx list <amd-gfx at lists.freedesktop.org>
> Subject: Re: [PATCH 1/2] drm/amdgpu: Enable scatter gather display support
> 
> Am 06.03.2018 um 18:51 schrieb Michel Dänzer:
> > On 2018-03-06 06:44 PM, Christian König wrote:
> >> Am 06.03.2018 um 18:22 schrieb Li, Samuel:
> >>>> addition to that I agree with Michel that the module parameter is
> >>>> overkill.
> >>> That I already explained. Currently SG display feature needs to
> >>> provide options for all kinds of use cases. All amd drivers so far
> >>> provides options, and the default configuration is actually to
> >>> allocate everything from GTT when possible.
> >> That isn't job of the kernel to have this parameter. Saying that we
> >> should probably add a DDX and/or environment option to control that.
> > Why would we need that? It's the kernel driver's job to handle this as
> > needed.
> 
> Buffer placement is specified by the DDX/Mesa, when we override that in
> the kernel we just force unnecessary buffer moves.
> 
> Regards,
> Christian.