[Mesa-dev] [PATCH 1/2] freedreno: a2xx: fix crash on first clear

[Rob Clark]

On Wed, Jun 20, 2018 at 10:01 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Wed, Jun 20, 2018 at 9:56 AM, Rob Clark <robdclark at gmail.com> wrote:
>> On Tue, Jun 19, 2018 at 9:02 PM, Jonathan Marek <jonathan at marek.ca> wrote:
>>> blend can be NULL, so check for that
>>
>> hmm, which case are you hitting that?  From a quick look I think
>> a3xx-a5xx would have the same issue.  Maybe we should just init
>> ctx->blend to a dummy state obj when the ctx is created?
>
> This generally happens with clears. A long time ago, st/mesa got
> rejiggered slightly, and a glClear() could happen before a blend state
> was bound. Many drivers implement clear by doing some amount of
> validation, so they have to watch out. I'm sure a3xx+ were already
> fixed for this, but not surprising that a2xx still has issues.
>

ahh, ok.. that makes more sense.. a5xx uses hw blitter for clears, and
a3xx-a4xx use u_blitter.. a2xx is doing something a bit more custom
since (iirc) I didn't know how to write depth from frag shader..

BR,
-R