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In-Reply-To: <20190429143757.yljjfsgobhi23xnb@sirius.home.kraxel.org>
From:   Daniel Vetter <daniel@ffwll.ch>
Date:   Mon, 29 Apr 2019 16:44:40 +0200
Message-ID: <CAKMK7uE_+-pFuVrqznj9ZbRxwyNM9mRhoY-y4xCBjjY9Z-sNDg@mail.gmail.com>
Subject: Re: [Spice-devel] [PATCH] Revert "drm/qxl: drop prime import/export callbacks"
To:     Gerd Hoffmann <kraxel@redhat.com>
Cc:     David Airlie <airlied@linux.ie>,
        open list <linux-kernel@vger.kernel.org>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        "open list:DRM DRIVER FOR QXL VIRTUAL GPU" 
        <virtualization@lists.linux-foundation.org>,
        David Airlie <airlied@redhat.com>,
        "open list:DRM DRIVER FOR QXL VIRTUAL GPU" 
        <spice-devel@lists.freedesktop.org>
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On Mon, Apr 29, 2019 at 4:38 PM Gerd Hoffmann <kraxel@redhat.com> wrote:
>
>   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?

Oh sure, acked-by: me. Sorry forgot to supply that ...
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch