linux-kernel - Re: [PATCH v2 5/5] drm/vc4: Expose dma-buf fences for V3D rendering.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87y3v4b52x.fsf@eliezer.anholt.net>
Date:   Thu, 13 Apr 2017 10:16:54 -0700
From:   Eric Anholt <eric@...olt.net>
To:     Daniel Vetter <daniel@...ll.ch>
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 5/5] drm/vc4: Expose dma-buf fences for V3D rendering.

Daniel Vetter <daniel@...ll.ch> writes:

> On Wed, Apr 12, 2017 at 12:12:02PM -0700, Eric Anholt wrote:
>> This is needed for proper synchronization with display on another DRM
>> device (pl111 or tinydrm) with buffers produced by vc4 V3D.  Fixes the
>> new igt vc4_dmabuf_poll testcase, and rendering of one of the glmark2
>> desktop tests on pl111+vc4.
>> 
>> This doesn't yet introduce waits on other device's fences before vc4's
>> rendering/display, because I don't have testcases for them.
>> 
>> v2: Reuse dma_fence_free(), retitle commit message to clarify that
>>     it's not a full dma-buf fencing implementation yet.
>> 
>> Signed-off-by: Eric Anholt <eric@...olt.net>
>
> Double-checked a few things in your ww_mutex scheme, seems are correct.
> And testing with CONFIG_DEBUG_WW_MUTEX_SLOWPATH should catch any kind of
> fumbles in your error paths. I didnt do a full review, so just

Yeah, the lockdep and WW debug options were incredibly useful (and I
should probably go turn them off now).

Download attachment "signature.asc" of type "application/pgp-signature" (833 bytes)