From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Christian_K=c3=b6nig?= Subject: Re: [radeon r100] when ring test fails, provide users with option to test Date: Wed, 2 Dec 2015 09:57:14 +0100 Message-ID: <565EB26A.9030000@amd.com> References: <20151128205840.GA26757@amd> <565B56A5.4080702@amd.com> <20151129222235.GA25692@amd> <565C0B5A.2040103@amd.com> <20151201100110.GE21222@amd> <565E620D.3090605@daenzer.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <565E620D.3090605@daenzer.net> Sender: linux-kernel-owner@vger.kernel.org To: =?UTF-8?Q?Michel_D=c3=a4nzer?= , Pavel Machek Cc: alexander.deucher@amd.com, Trivial patch monkey , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On 02.12.2015 04:14, Michel D=C3=A4nzer wrote: > On 01.12.2015 19:01, Pavel Machek wrote: >> On Mon 2015-11-30 09:39:54, Christian K=C3=B6nig wrote: >>> On 29.11.2015 23:22, Pavel Machek wrote: >>>> On Sun 2015-11-29 20:48:53, Christian K=C3=B6nig wrote: >>>>> On 28.11.2015 21:58, Pavel Machek wrote: >>>>>> Ring test failure is often caused by too high agpmode. Tell the = user >>>>>> what to try. >>>>>> >>>>>> Signed-off-by: Pavel Machek >>>>> NAK, the ring test can fail for any number of reasons and the agp= mode is >>>>> actually rather unlikely to be the cause. >>>> Well, when I asked on the list "why this is happened" I got "umm, >>>> noone knows" response that was not exactly helpful. And then someo= ne >>>> told me about agpmode. >>>> >>>> If you know about the reasons it can fail, could you list them nea= r >>>> the DRM_ERROR, at least as a comment? >>> Well as I said, that could be any number of reasons. Some of them e= ven >>> completely unrelated to the driver itself. >>> >>> E.g. BIOS setting, faulty hardware, problems with the writeback etc= =2E.. There >>> is really not a list you could give here. >>> >>> Lowering the agpmode usually helps more to prevent random corruptio= ns and >>> problems under load. >> Take a look at >> >> http://www.gossamer-threads.com/lists/linux/kernel/2197183 >> >> . I had a problem, you did not know how to debug it, but it already >> happened to pebolle at tiscali ... and yes, it was agpmode. That >> problem is clearly more common then you realize... So this should go >> in. > I agree with Christian, but at the very least, agpmode must not be > mentioned if AGP isn't being used in the first place, i.e. either the > GPU isn't AGP or is being forced to PCI(e) mode. Well maybe to explain the background, r100_ring_test() is used for a=20 whole bunch of different hardware generations. Most of them doesn't even have AGP, so mentioning this here would be=20 even confusion for the majority of users. Regards, Christian.