Re: [Spice-devel] [PATCH] Revert "drm/qxl: drop prime import/export callbacks"

From: Gerd Hoffmann
Date: Mon Apr 29 2019 - 10:38:02 EST


Hi,

> > More useful would be some way to signal this self-reimport capability
> > to userspace somehow. See DRM_PRIME_CAP_LOCAL patch.
>
> Userspace is supposed to test whether import/export works for a
> specific combo, not blindly assume it does and then keel over. I think
> we need to fix that, not add more flags - there's lots of reasons why
> a given pair of devices can't share buffers (e.g. all the contiguous
> allocations stuff on socs).

Ok. Lets scratch the DRM_PRIME_CAP_LOCAL idea then and blame userspace
instead.

> > Right now I have the choice to set DRM_PRIME_CAP_{IMPORT,EXPORT}, in
> > which case some userspace assumes it can do cross-driver export/import
> > and trips over that not working. Or I do not set
> > DRM_PRIME_CAP_{IMPORT,EXPORT}, which breaks DRI3 ...
>
> Yeah that's not an option.

Good. Can I get an ack for this patch then, as it unbreaks DRI3 with qxl?

thanks,
Gerd