From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oded Gabbay Subject: Re: [PATCH] drm/radeon: don't init gpuvm if accel is disabled Date: Thu, 29 Jan 2015 15:58:30 +0200 Message-ID: <54CA3C86.6030802@amd.com> References: <1422474095-20982-1-git-send-email-alexander.deucher@amd.com> <54C9E555.5090307@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: stable-owner@vger.kernel.org To: "Deucher, Alexander" , Alex Deucher , "dri-devel@lists.freedesktop.org" Cc: "stable@vger.kernel.org" List-Id: dri-devel@lists.freedesktop.org On 01/29/2015 03:54 PM, Deucher, Alexander wrote: >> -----Original Message----- >> From: Gabbay, Oded >> Sent: Thursday, January 29, 2015 2:46 AM >> To: Alex Deucher; dri-devel@lists.freedesktop.org >> Cc: Deucher, Alexander; stable@vger.kernel.org >> Subject: Re: [PATCH] drm/radeon: don't init gpuvm if accel is disabled >> >> >> >> On 01/28/2015 09:41 PM, Alex Deucher wrote: >>> If acceleration is disabled, it does not make sense >>> to init gpuvm since nothing will use it. Moreover, >>> if radeon_vm_init() gets called it uses accel to try >>> and clear the pde tables, etc. which results in a bug. >>> >>> Bug: >>> https://bugs.freedesktop.org/show_bug.cgi?id=88786 >>> >>> Signed-off-by: Alex Deucher >>> Cc:stable@vger.kernel.org >> Alex, >> What is accel ? > > If the ring tests fail and for some reason the IPs (e.g., gfx or sdma) are not available, the driver disables acceleration and basically falls back to modesetting only. > >> Is there a situation where accel is disabled and HSA should work ? e.g. >> headless >> mode ? > > No. We only disable acceleration if we can't get the IPs (gfx, sdma) initialized. Headless has nothing to do with acceleration in this context. > > Alex > OK, thanks for the explanation. Oded