From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A52F5C38A2A for ; Fri, 8 May 2020 15:58:31 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 83D1220CC7 for ; Fri, 8 May 2020 15:58:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 83D1220CC7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 29E4C6EB2D; Fri, 8 May 2020 15:58:31 +0000 (UTC) Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3E0F36EB2D for ; Fri, 8 May 2020 15:58:29 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from localhost (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP (TLS) id 21153384-1500050 for multiple; Fri, 08 May 2020 16:58:28 +0100 MIME-Version: 1.0 In-Reply-To: <87blmy4e9t.fsf@gaia.fi.intel.com> References: <20200508092933.738-1-chris@chris-wilson.co.uk> <20200508092933.738-4-chris@chris-wilson.co.uk> <87blmy4e9t.fsf@gaia.fi.intel.com> To: Mika Kuoppala , intel-gfx@lists.freedesktop.org From: Chris Wilson Message-ID: <158895350540.30605.6858581872635477697@build.alporthouse.com> User-Agent: alot/0.8.1 Date: Fri, 08 May 2020 16:58:25 +0100 Subject: Re: [Intel-gfx] [PATCH 4/9] drm/i915: Tidy awaiting on dma-fences X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Quoting Mika Kuoppala (2020-05-08 16:50:22) > Chris Wilson writes: > > > Just tidy up the return handling for completed dma-fences. While it may > > return errors for invalid fence, we already know that we have a good > > fence and the only error will be an already signaled fence. > > > > Signed-off-by: Chris Wilson > > --- > > drivers/gpu/drm/i915/i915_sw_fence.c | 10 ++++------ > > 1 file changed, 4 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c > > index 7daf81f55c90..295b9829e2da 100644 > > --- a/drivers/gpu/drm/i915/i915_sw_fence.c > > +++ b/drivers/gpu/drm/i915/i915_sw_fence.c > > @@ -546,13 +546,11 @@ int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence, > > cb->fence = fence; > > i915_sw_fence_await(fence); > > > > - ret = dma_fence_add_callback(dma, &cb->base, __dma_i915_sw_fence_wake); > > - if (ret == 0) { > > - ret = 1; > > - } else { > > + ret = 1; > > + if (dma_fence_add_callback(dma, &cb->base, __dma_i915_sw_fence_wake)) { > > + /* fence already signaled */ > > This seems to hold water now. Perhaps for eternity. > > But how about if (dma_fence_add_callback() == -ENOENT) ret = 0; else > GEM_BUG_ON()? Because that's just ugly. If we do not install the callback, we need to signal the callback. The only question is whether or not an error there is moot -- we either have the fence, or we would have exploded. The fence callback will be propagating errors along the fence. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx