From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 63CA560764 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=daenzer.net Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752430AbeFFPDZ (ORCPT + 25 others); Wed, 6 Jun 2018 11:03:25 -0400 Received: from mail.netline.ch ([148.251.143.178]:47188 "EHLO netline-mail3.netline.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751973AbeFFPDV (ORCPT ); Wed, 6 Jun 2018 11:03:21 -0400 Subject: Re: Kernel and ADM hardware roulette ( was AMD graphics performance regression in 4.15 and later ) To: =?UTF-8?Q?Christian_K=c3=b6nig?= , Gabriel C Cc: Jean-Marc Valin , Dave Airlie , Felix Kuehling , LKML , dri-devel@lists.freedesktop.org, alexander.deucher@amd.com, Andrew Morton , Linus Torvalds References: <516cddbe-73c2-01f3-a552-0d9fd75ce63a@amd.com> <8f7d00f9-992f-cc07-6bd0-b1b47c5d2ccf@amd.com> From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Message-ID: Date: Wed, 6 Jun 2018 17:03:16 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <8f7d00f9-992f-cc07-6bd0-b1b47c5d2ccf@amd.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-06-06 04:44 PM, Christian König wrote: > Am 06.06.2018 um 16:12 schrieb Michel Dänzer: >> On 2018-06-06 03:33 PM, Gabriel C wrote: >>> 2018-06-06 14:19 GMT+02:00 Christian König : >>>> Am 06.06.2018 um 14:08 schrieb Gabriel C: >>>>> 2018-06-06 13:33 GMT+02:00 Christian König : >>>>>> Am 06.06.2018 um 13:28 schrieb Gabriel C: >> >>>>> http://ftp.frugalware.org/pub/other/people/crazy/radeon/dmesg-iommu-sr-iov-off.txt >>>>> >>>>> >>>>> http://ftp.frugalware.org/pub/other/people/crazy/radeon/dmesg-iommu-sr-iov-on.txt >>>>> >>>>> >>>>> Also nothing else changed in that setup just testing kernel 4.17. >>>> >>>> >>>> That has nothing TODO with the driver nor the original bug you >>>> reported. The >>>> problem is that SME is active and that is currently not supported at >>>> all >>>> with a that hardware. >>> >>> Ok .. so are we playing now kernel an AMD Hardware roulette on each >>> release ? >>> >>> SME was like this in kernel 4.16.x here and all worked. >> >> If that is true, again please bisect which commit broke it. >> >> All the reports I've seen before this indicated that at least amdgpu >> has never worked with SME (which BTW doesn't mean it's never going to >> work or that we don't want to support it, just that as far as we know >> it's currently not working). > > At least in theory it should work when we use the coherent DMA allocator. > > When that really worked before, so the most likely commit which broke > this is: > > commit fd5fd480dd8fe4910546e7b080b3ae345e57fe9f > Author: Chunming Zhou > Date:   Fri Feb 9 10:44:09 2018 +0800 > >     drm/amdgpu: only enable swiotlb alloc when need v2 > >     get the max io mapping address of system memory to see if it is over >     our card accessing range. >     v2: move checking later > >     Signed-off-by: Chunming Zhou >     Reviewed-by: Monk Liu >     Reviewed-by: Christian König >     Signed-off-by: Alex Deucher > > Currently looking into how we could somehow improve this detection. I guess this could fit for Gabriel, but e.g. https://bugs.freedesktop.org/104437 says amdgpu was already broken with SME in 4.15, if not 4.14 (I suspect there was simply no SME support earlier). -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer