Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932154AbaGWHJX (ORCPT ); Wed, 23 Jul 2014 03:09:23 -0400 Received: from mail-ig0-f182.google.com ([209.85.213.182]:37165 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753477AbaGWHJW (ORCPT ); Wed, 23 Jul 2014 03:09:22 -0400 MIME-Version: 1.0 X-Originating-IP: [84.73.67.144] In-Reply-To: <53CF5EFE.6070307@canonical.com> References: <20140709093124.11354.3774.stgit@patser> <20140709122953.11354.46381.stgit@patser> <53CE2421.5040906@amd.com> <20140722114607.GL15237@phenom.ffwll.local> <20140722115737.GN15237@phenom.ffwll.local> <53CE56ED.4040109@vodafone.de> <20140722132652.GO15237@phenom.ffwll.local> <53CE6AFA.1060807@vodafone.de> <53CE84AA.9030703@amd.com> <53CE8A57.2000803@vodafone.de> <53CF58FB.8070609@canonical.com> <53CF5B9F.1050800@amd.com> <53CF5EFE.6070307@canonical.com> Date: Wed, 23 Jul 2014 09:09:21 +0200 Message-ID: Subject: Re: [Nouveau] [PATCH 09/17] drm/radeon: use common fence implementation for fences From: Daniel Vetter To: Maarten Lankhorst Cc: =?UTF-8?Q?Christian_K=C3=B6nig?= , =?UTF-8?Q?Christian_K=C3=B6nig?= , Dave Airlie , Thomas Hellstrom , nouveau , LKML , dri-devel , Ben Skeggs , "Deucher, Alexander" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 23, 2014 at 9:06 AM, Maarten Lankhorst wrote: >> Can we somehow avoid the need to call fence_signal() at all? The interrupts at least on radeon are way to unreliable for such a thing. Can enable_signalling fail? What's the reason for fence_signaled() in the first place? > It doesn't need to be completely reliable, or finish immediately. > > And any time wake_up_all(&rdev->fence_queue) is called all the fences that were enabled will be rechecked. I raised this already somewhere else, but should we have some common infrastructure in the core fence code to recheck fences periodically? radeon doesn't seem to be the only hw where this isn't reliable enough. Of course timer-based rechecking would only work if the driver provides the fence->signalled callback to recheck actual fence state. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/