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=-7.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E8EEAC43603 for ; Thu, 19 Dec 2019 13:54:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E82AC218AC for ; Thu, 19 Dec 2019 13:54:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=xenosoft.de header.i=@xenosoft.de header.b="az7RU2Ae" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E82AC218AC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xenosoft.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65AC48E016F; Thu, 19 Dec 2019 08:54:53 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 60AC68E00F5; Thu, 19 Dec 2019 08:54:53 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4FA288E016F; Thu, 19 Dec 2019 08:54:53 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0206.hostedemail.com [216.40.44.206]) by kanga.kvack.org (Postfix) with ESMTP id 3C3208E00F5 for ; Thu, 19 Dec 2019 08:54:53 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id DDCF9181AC9CC for ; Thu, 19 Dec 2019 13:54:52 +0000 (UTC) X-FDA: 76282036824.28.bat22_64aff2486731b X-HE-Tag: bat22_64aff2486731b X-Filterd-Recvd-Size: 4092 Received: from mo4-p01-ob.smtp.rzone.de (mo4-p01-ob.smtp.rzone.de [85.215.255.50]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Thu, 19 Dec 2019 13:54:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1576763690; s=strato-dkim-0002; d=xenosoft.de; h=In-Reply-To:Date:Message-ID:References:Cc:To:From:Subject: X-RZG-CLASS-ID:X-RZG-AUTH:From:Subject:Sender; bh=kI2ukjRy7KCFsfSWtfjMgsGPbi2sbVneeGOg1X7LIV8=; b=az7RU2Ae7GyWgkCNcH5LUe/Ye9B39nZpMjosVRZyU/F0P6P8yTTiDaYuo+OxPRWQ53 gqSFZJOgnkUkURqEtkaKb4Gu1eQQTnMyHjVVbX3ccOgtHuMcl9UoPQp7yHbPku+TsshU zQR5Xe4l1yoS+ekhd7yaIKdmnGabBokg3lyR3lYcucpg7YKWUclpwODKm0kLlrta6njR Wn2FRU53Yo3SiSM2PnN5YpAnWt467k+m86S7dGRNRNtSlV3gAG2X+WQ+OA1PaDRRaYP4 p25hlOrMoVZ2eHEaInLVRcbqXfe5AQ+gKzvnKXJ28QLpjhEyOQtAl8c6JMl+OfxgzIE6 bX/A== X-RZG-AUTH: ":L2QefEenb+UdBJSdRCXu93KJ1bmSGnhMdmOod1DhGM4l4Hio94KKxRySfLxnHfJ+Dkjp5DdBJSrwuuqxvPhSIk4IhhIsapUrtwdiemkXf6zUCQ==" X-RZG-CLASS-ID: mo00 Received: from [IPv6:2a02:8109:89c0:ebfc:141e:1690:4104:28ad] by smtp.strato.de (RZmta 46.1.1 AUTH) with ESMTPSA id 40080evBJDsS14t (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Thu, 19 Dec 2019 14:54:28 +0100 (CET) Subject: Re: use generic DMA mapping code in powerpc V4 From: Christian Zigotzky To: Michael Ellerman , Christoph Hellwig , Benjamin Herrenschmidt , Paul Mackerras Cc: linux-arch@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "R.T.Dickinson" , "contact@a-eon.com" , mad skateman , Darren Stevens References: <20181114082314.8965-1-hch@lst.de> <20181127074253.GB30186@lst.de> <87zhttfonk.fsf@concordia.ellerman.id.au> <535776df-dea3-eb26-6bf3-83f225e977df@xenosoft.de> Message-ID: Date: Thu, 19 Dec 2019 14:54:27 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <535776df-dea3-eb26-6bf3-83f225e977df@xenosoft.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: de-DE X-Bogosity: Ham, tests=bogofilter, spamicity=0.002385, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi All, We still have some issues with PCI cards in our FSL P5020 and P5040 systems since the DMA mapping updates. [1, 2] We have to limit the RAM to 3500MB for some problematic PCI cards. (kernel boot argument 'mem=3500M') The problematic DMA mapping code was added with the PowerPC updates 4.21-1 to the official kernel source code last year. [3] We have created a bug report. [4] The old 4.x kernels aren't affected because they use the old DMA code. Please check the new DMA code again. Thanks, Christian [1] http://forum.hyperion-entertainment.com/viewtopic.php?f=58&p=49486#p49486 [2] http://forum.hyperion-entertainment.com/viewtopic.php?f=58&t=4349&start=50#p49099 [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8d6973327ee84c2f40dd9efd8928d4a1186c96e2 [4] https://bugzilla.kernel.org/show_bug.cgi?id=205201 On 28 November 2018 at 4:55 pm, Christian Zigotzky wrote: > On 28 November 2018 at 12:05PM, Michael Ellerman wrote: >> Nothing specific yet. >> >> I'm a bit worried it might break one of the many old obscure platforms >> we have that aren't well tested. >> > Please don't apply the new DMA mapping code if you don't be sure if it > works on all supported PowerPC machines. Is the new DMA mapping code > really necessary? It's not really nice, to rewrote code if the old > code works perfect. We must not forget, that we work for the end > users. Does the end user have advantages with this new code? Is it > faster? The old code works without any problems. I am also worried > about this code. How can I test this new DMA mapping code? > > Thanks > >