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=-2.2 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2F6F4C7618F for ; Thu, 18 Jul 2019 20:26:32 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 025B221019 for ; Thu, 18 Jul 2019 20:26:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 025B221019 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=charter.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id BEF371E2B; Thu, 18 Jul 2019 20:26:31 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 031021D8E for ; Thu, 18 Jul 2019 20:26:14 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from impout009.msg.chrl.nc.charter.net (impout009aa.msg.chrl.nc.charter.net [47.43.20.33]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 4586F887 for ; Thu, 18 Jul 2019 20:26:14 +0000 (UTC) Received: from [10.10.100.101] ([24.236.195.206]) by cmsmtp with ESMTPA id oCyiheBYfiYmuoCyihrjhs; Thu, 18 Jul 2019 20:26:13 +0000 Authentication-Results: charter.net; none X-Authority-Analysis: v=2.3 cv=S41tP7kP c=1 sm=1 tr=0 a=mQKZifbrf9Y32dM5lNTaRA==:117 a=mQKZifbrf9Y32dM5lNTaRA==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=IkcTkHD0fZMA:10 a=3fyaaF4VAAAA:8 a=zd2uoN0lAAAA:8 a=DAWNvU-7WsZP1TvUpVoA:9 a=QEXdDO2ut3YA:10 a=jOuFdahVONy5WApiBME_:22 From: Al Farleigh Subject: Re: x86-64 kernel dma issue; bisected To: Christoph Hellwig References: <20190718093129.GA25126@infradead.org> Message-ID: <93c60ba2-44d3-25ce-b174-137a9eed7831@charter.net> Date: Thu, 18 Jul 2019 16:26:12 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190718093129.GA25126@infradead.org> Content-Language: en-US X-CMAE-Envelope: MS4wfHJK2ZN5Cj3oRtlzCGBXcm4dxbJdcQokxUu6y6xb1ebvrqnGPDBurCkJ3bZaw5ClY72+fQjIpSVxBrWxVtTKp5+DHpe9fBX8rgPw6QpxvjgxAamk5KkY tWr5Gd1Idpyb4zaiFnq1okCT8P+cc8peA2ppHH2zUsDHnKiMhfKw3yfjVF5rk0Om3CQgBJTaFNbcxdRmkbYea8/6VzqxV+6eXsT3P8dZ+U+x/JS6PXbI4FmM dpbwQWUA2wX9cEiuy7K10Q== Cc: Tom Lendacky , iommu@lists.linux-foundation.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On 7/18/19 5:31 AM, Christoph Hellwig wrote: > On Tue, Jul 16, 2019 at 10:43:33PM -0400, Al Farleigh wrote: >> re: the dma-direct code commit below >> >> I have bisected the kernel to isolate a PCI board problem on my AMD x86-64 >> ASROCK system. The board worked at (Fedora kernel) 4.18.16 but stopped when >> moving to (Fedora kernel) 5.0. I then used (git/torvalds/linux) 4.20-rc4 or >> so to locate the fault via bisect. >> >> I now have two kernels, good/bad, that straddle the commit. >> >> I was asked to try v5.2 just in case it was fixed; I compiled it and the >> fault appears to still be present. >> >> Simply, mpeg video does not stream from board; no errors, but no video. >> >> My work is documented at >> https://bugs.kde.org/show_bug.cgi?id=408004 > > I've looked through that log but I'm still not sure what driver > you are actually using for video capture. Am I right in that your > are using the saa7134 driver based on the dmesg? > > That driver uses a 32-bit DMA mask, so we should be bounce buffering. > > We recently had a bug with the AMD memory encryption and the encrypted > bit, are you using that? The "Freeing unused decrypted memory:" message > somehow suggests that but I can't find where that would come from by a > simple grep. If your are using AMD memory encryption or are not sure > please try the patch below: > Hello; I installed the patch on v5.2, verified by eye it got applied, recompiled, and found no change; that is, the video stream doesn't display. I also went back and verified my known good v4.20-rc4 kernel still worked, and my known bad v4.20-rc4 stayed bad. No changes. I will note that the video has once or twice but extremely rarely had started on the bad kernels; maybe a timing or race, or somehow being set up from a previous boot; I try to power off between tests to make sure system starts from a known, uncontaminated environment. Regards, Al Farleigh > --- >>>From 9087c37584fb7d8315877bb55f85e4268cc0b4f4 Mon Sep 17 00:00:00 2001 > From: Tom Lendacky > Date: Wed, 10 Jul 2019 19:01:19 +0000 > Subject: dma-direct: Force unencrypted DMA under SME for certain DMA masks > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu