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=-10.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 ADD5CC433E0 for ; Tue, 21 Jul 2020 15:44:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C7F920771 for ; Tue, 21 Jul 2020 15:44:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="ElYOyoi4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729180AbgGUPoW (ORCPT ); Tue, 21 Jul 2020 11:44:22 -0400 Received: from mail29.static.mailgun.info ([104.130.122.29]:24316 "EHLO mail29.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726029AbgGUPoV (ORCPT ); Tue, 21 Jul 2020 11:44:21 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1595346261; h=In-Reply-To: Content-Type: MIME-Version: References: Message-ID: Subject: Cc: To: From: Date: Sender; bh=rdC4JoLgL+0mT3i14s7ghddjUga20hFANQNIf9sHBoA=; b=ElYOyoi4cmnLW0R41wIYVLUXCFSJGJhgq/Mmkvr7sPdnrDl279HOAzL9sCh2HYYg/0m8yReO 9XqRxnYJhvXk40+Y+pSrvPh507Gs4GFiFf4/XnPzxmOg8xqqN0MtYhgMb1LTNEhg0GqT2RvH mXDZNDuttc8z+2N/O7y6bFJn8IQ= X-Mailgun-Sending-Ip: 104.130.122.29 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-west-2.postgun.com with SMTP id 5f170d540cb8533c3baedcd2 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 21 Jul 2020 15:44:20 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 536B5C433AD; Tue, 21 Jul 2020 15:44:20 +0000 (UTC) Received: from jcrouse1-lnx.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jcrouse) by smtp.codeaurora.org (Postfix) with ESMTPSA id 819FDC433C6; Tue, 21 Jul 2020 15:44:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 819FDC433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=jcrouse@codeaurora.org Date: Tue, 21 Jul 2020 09:44:15 -0600 From: Jordan Crouse To: Konrad Dybcio Cc: Bjorn Andersson , Will Deacon , skrzynka@konradybcio.pl, Robin Murphy , Joerg Roedel , Rob Herring , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, DTML , Linux Kernel Mailing List , John Stultz Subject: Re: [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init Message-ID: <20200721154415.GA5758@jcrouse1-lnx.qualcomm.com> Mail-Followup-To: Konrad Dybcio , Bjorn Andersson , Will Deacon , skrzynka@konradybcio.pl, Robin Murphy , Joerg Roedel , Rob Herring , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, DTML , Linux Kernel Mailing List , John Stultz References: <20200704122809.73794-1-konradybcio@gmail.com> <20200704130922.GB21333@willie-the-truck> <20200705033511.GR388985@builder.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 21, 2020 at 05:04:11PM +0200, Konrad Dybcio wrote: > So.. is this a no-no? > > I of course would like to omit this entirely, but SMMUs on sdm630 and > friends are REALLY picky.. What seems to happen is that when the > driver tries to do things the "standard" way, hypervisor decides to > hang the platform or force a reboot. Not very usable. > > > This thing is needed for the platform to even boot properly and one > more [1] is required to make mdss work with video mode panels (the > fact that CMD-mode panels work is kinda hilarious to me). > > To be honest, there are even more qcom quirks (of which at least > qcom,dynamic and qcom-use-3-lvl-tables are used on 630).. [2] > > Looking forward to your answers and possibly better solutions. Nobody is disputing that the qcom SMMUs don't have their share of quirks but it seems that the community has mostly settled on the agreement that there are better ways to solve this than a handful of device tree properties. The current focus has been on moving more of the SMMU specific bits into the arm-smmu-qcom implementation [1] and I think that is the right way to go. As for the other quirks we can probably discuss those on a case by case basis. I doubt you will find much enthusiasm for qcom,use-3-lvl-tables and I've been working on replacing qcom,dynamic with something much better [2]. [1] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046304.html [2] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046756.html Jordan > [1] https://github.com/konradybcio/linux/commit/83ac38af259968f92b6a8b7eab90096c78469f87 > [2] https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.7.1.r1/drivers/iommu/arm-smmu.c#L404-L415 > > Regards > Konrad -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project 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=-10.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 69BBBC433E4 for ; Tue, 21 Jul 2020 15:44:38 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 30C0320720 for ; Tue, 21 Jul 2020 15:44:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="N3TaMJts" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 30C0320720 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 0CEE6886EE; Tue, 21 Jul 2020 15:44:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8IAOkJ6mZxnq; Tue, 21 Jul 2020 15:44:37 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 79C7A886DF; Tue, 21 Jul 2020 15:44:37 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 59D26C088E; Tue, 21 Jul 2020 15:44:37 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id A7B84C016F for ; Tue, 21 Jul 2020 15:44:35 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 7C46E87E3B for ; Tue, 21 Jul 2020 15:44:35 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YpqeE7UVLHnP for ; Tue, 21 Jul 2020 15:44:34 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail29.static.mailgun.info (mail29.static.mailgun.info [104.130.122.29]) by whitealder.osuosl.org (Postfix) with ESMTPS id 8966B80790 for ; Tue, 21 Jul 2020 15:44:30 +0000 (UTC) DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1595346274; h=In-Reply-To: Content-Type: MIME-Version: References: Message-ID: Subject: Cc: To: From: Date: Sender; bh=rdC4JoLgL+0mT3i14s7ghddjUga20hFANQNIf9sHBoA=; b=N3TaMJts8zy2wthTRejtLd6yJGE0Jda8ziqRVj+1z4PysxvAdqO7T1sUgi46mAxMbsC5nghC 5CV1Wo0NkwqrEzhCEnhp8K+UtTQid/rF9UNO3hSIwttkF195c3/Q2WzX+rZjVp4TFH6RtfRr HVraFQsb3EijmHlP+oT1CACjk60= X-Mailgun-Sending-Ip: 104.130.122.29 X-Mailgun-Sid: WyI3NDkwMCIsICJpb21tdUBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-west-2.postgun.com with SMTP id 5f170d54d50c36e729f2b775 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 21 Jul 2020 15:44:20 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 446F8C43395; Tue, 21 Jul 2020 15:44:20 +0000 (UTC) Received: from jcrouse1-lnx.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jcrouse) by smtp.codeaurora.org (Postfix) with ESMTPSA id 819FDC433C6; Tue, 21 Jul 2020 15:44:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 819FDC433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=jcrouse@codeaurora.org Date: Tue, 21 Jul 2020 09:44:15 -0600 From: Jordan Crouse To: Konrad Dybcio Subject: Re: [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init Message-ID: <20200721154415.GA5758@jcrouse1-lnx.qualcomm.com> Mail-Followup-To: Konrad Dybcio , Bjorn Andersson , Will Deacon , skrzynka@konradybcio.pl, Robin Murphy , Joerg Roedel , Rob Herring , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, DTML , Linux Kernel Mailing List , John Stultz References: <20200704122809.73794-1-konradybcio@gmail.com> <20200704130922.GB21333@willie-the-truck> <20200705033511.GR388985@builder.lan> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Cc: DTML , skrzynka@konradybcio.pl, Will Deacon , Linux Kernel Mailing List , iommu@lists.linux-foundation.org, Rob Herring , John Stultz , Robin Murphy , linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, Jul 21, 2020 at 05:04:11PM +0200, Konrad Dybcio wrote: > So.. is this a no-no? > > I of course would like to omit this entirely, but SMMUs on sdm630 and > friends are REALLY picky.. What seems to happen is that when the > driver tries to do things the "standard" way, hypervisor decides to > hang the platform or force a reboot. Not very usable. > > > This thing is needed for the platform to even boot properly and one > more [1] is required to make mdss work with video mode panels (the > fact that CMD-mode panels work is kinda hilarious to me). > > To be honest, there are even more qcom quirks (of which at least > qcom,dynamic and qcom-use-3-lvl-tables are used on 630).. [2] > > Looking forward to your answers and possibly better solutions. Nobody is disputing that the qcom SMMUs don't have their share of quirks but it seems that the community has mostly settled on the agreement that there are better ways to solve this than a handful of device tree properties. The current focus has been on moving more of the SMMU specific bits into the arm-smmu-qcom implementation [1] and I think that is the right way to go. As for the other quirks we can probably discuss those on a case by case basis. I doubt you will find much enthusiasm for qcom,use-3-lvl-tables and I've been working on replacing qcom,dynamic with something much better [2]. [1] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046304.html [2] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046756.html Jordan > [1] https://github.com/konradybcio/linux/commit/83ac38af259968f92b6a8b7eab90096c78469f87 > [2] https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.7.1.r1/drivers/iommu/arm-smmu.c#L404-L415 > > Regards > Konrad -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-10.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 AB59CC433E0 for ; Tue, 21 Jul 2020 15:46:30 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 79B8A2070A for ; Tue, 21 Jul 2020 15:46:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Thor6b3X"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="iGUg0eae" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79B8A2070A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6gp+FqEU9evq00ngSDvY+FfJz04vIu62uvYQG4aAKKw=; b=Thor6b3Xz041yT3uUZjUmcdik +H+5Dhxml+ZZHpSDg/9S0Fjb566X7d289pEY9p/nRy9WeaXtXhugq9Q/+ypyVAQ0y28U7uuiqHOdc aAu/lPIlVQZ5MIXqd7yn/SRU48Y1VgeKourLVnoKh30G8Pd1FaO1VdkbZYwOhYLjmFfkOsv37pz86 HRLiPAyAo54eUU234xprO8gVpK87zyM2auL7Dtx/q/Mno+zh0EPvWUxAeqSDs6wTILDj6ftPuh9ib Gd+oLAzcSI9OCIsRV9UKYKdtaRswWUxlpky1Y/FQ+sthn53bMcz/hotnhc+hF5VCT0nRWG1r6LnnZ aiL3M1UxQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxuRk-0006Zt-8i; Tue, 21 Jul 2020 15:44:48 +0000 Received: from m43-7.mailgun.net ([69.72.43.7]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxuRc-0006YY-PA for linux-arm-kernel@lists.infradead.org; Tue, 21 Jul 2020 15:44:45 +0000 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1595346284; h=In-Reply-To: Content-Type: MIME-Version: References: Message-ID: Subject: Cc: To: From: Date: Sender; bh=rdC4JoLgL+0mT3i14s7ghddjUga20hFANQNIf9sHBoA=; b=iGUg0eaewdZ2k8s+ZncUf1vLFl+tnIx9Coozns+FhZ63LGyLHxT0F/bh0hfrzg7aw5dVWnYh LYIJYGtrv1drKotRtGo1p6NEwXVRxtrhKMSIh1W0/iAPKMN9Il9ITG+u4QbBKWFWu2tE8BLS hwWaN0V3lmrr5qCoXYL4Sfl9xDQ= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyJiYzAxZiIsICJsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n13.prod.us-west-2.postgun.com with SMTP id 5f170d545912b3a405d230f3 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 21 Jul 2020 15:44:20 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 4FC8DC4339C; Tue, 21 Jul 2020 15:44:20 +0000 (UTC) Received: from jcrouse1-lnx.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jcrouse) by smtp.codeaurora.org (Postfix) with ESMTPSA id 819FDC433C6; Tue, 21 Jul 2020 15:44:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 819FDC433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=jcrouse@codeaurora.org Date: Tue, 21 Jul 2020 09:44:15 -0600 From: Jordan Crouse To: Konrad Dybcio Subject: Re: [PATCH 1/1] iommu/arm-smmu: Implement qcom,skip-init Message-ID: <20200721154415.GA5758@jcrouse1-lnx.qualcomm.com> Mail-Followup-To: Konrad Dybcio , Bjorn Andersson , Will Deacon , skrzynka@konradybcio.pl, Robin Murphy , Joerg Roedel , Rob Herring , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, DTML , Linux Kernel Mailing List , John Stultz References: <20200704122809.73794-1-konradybcio@gmail.com> <20200704130922.GB21333@willie-the-truck> <20200705033511.GR388985@builder.lan> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200721_114444_425280_C4E9DAE2 X-CRM114-Status: GOOD ( 21.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: DTML , skrzynka@konradybcio.pl, Will Deacon , Joerg Roedel , Linux Kernel Mailing List , Bjorn Andersson , iommu@lists.linux-foundation.org, Rob Herring , John Stultz , Robin Murphy , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jul 21, 2020 at 05:04:11PM +0200, Konrad Dybcio wrote: > So.. is this a no-no? > > I of course would like to omit this entirely, but SMMUs on sdm630 and > friends are REALLY picky.. What seems to happen is that when the > driver tries to do things the "standard" way, hypervisor decides to > hang the platform or force a reboot. Not very usable. > > > This thing is needed for the platform to even boot properly and one > more [1] is required to make mdss work with video mode panels (the > fact that CMD-mode panels work is kinda hilarious to me). > > To be honest, there are even more qcom quirks (of which at least > qcom,dynamic and qcom-use-3-lvl-tables are used on 630).. [2] > > Looking forward to your answers and possibly better solutions. Nobody is disputing that the qcom SMMUs don't have their share of quirks but it seems that the community has mostly settled on the agreement that there are better ways to solve this than a handful of device tree properties. The current focus has been on moving more of the SMMU specific bits into the arm-smmu-qcom implementation [1] and I think that is the right way to go. As for the other quirks we can probably discuss those on a case by case basis. I doubt you will find much enthusiasm for qcom,use-3-lvl-tables and I've been working on replacing qcom,dynamic with something much better [2]. [1] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046304.html [2] https://lists.linuxfoundation.org/pipermail/iommu/2020-July/046756.html Jordan > [1] https://github.com/konradybcio/linux/commit/83ac38af259968f92b6a8b7eab90096c78469f87 > [2] https://github.com/sonyxperiadev/kernel/blob/aosp/LA.UM.7.1.r1/drivers/iommu/arm-smmu.c#L404-L415 > > Regards > Konrad -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel