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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D9D0C4167D for ; Mon, 28 Nov 2022 08:15:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230103AbiK1IPv (ORCPT ); Mon, 28 Nov 2022 03:15:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229774AbiK1IPn (ORCPT ); Mon, 28 Nov 2022 03:15:43 -0500 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72B456151 for ; Mon, 28 Nov 2022 00:15:40 -0800 (PST) Received: by mail-pl1-x62c.google.com with SMTP id p24so5676719plw.1 for ; Mon, 28 Nov 2022 00:15:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=41dMnLlQhVdjKXFxljKHhsQK7EgN1jbnFbZkDumWU3k=; b=NCmqK9rQ94cfbvI1oGd7hVmrNMvAbjRG3S0lUj+b8ld9Mr0X+bVPi1WKUzclB49N2R 5eQps+vIbFLhlk5P2Z7NmEP/q8Bkra4og1rIheAvILOHGsCsXSo/R6WagfoL8DMlXoni SQqY9LYvVjLdl6sqtSkjt9AEwvJWMAGdW2rSj9qJB9igzYjtfLpWMqMkxkhm/F9adD51 JkWuj0AkF4hofIsGXNtu5nhAOIsMUBPYyjeTG56bDvXVXz+JJDk7m/Mq4eTohbQy0nCi qQum4GPrOKMwOH1OWDhLE9g9HzmSi2xHfYRx01zN7ahDenswr82aF3IR74gBh2qi66Tj AOAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=41dMnLlQhVdjKXFxljKHhsQK7EgN1jbnFbZkDumWU3k=; b=YMBCEwjlN5peESD1sZyJGPEpzMhBlDGGHo1G3I5hDde332ZHaXdovfY/XwqabqAjxL kILw5XXie6Nm+yGblWv8yMnaEoksa8p2+6ahkr3LB7TsiHVH/07RpLTZlJ+O/J2/c12k eNAsxeO1EsBy3+Imrm4efnFNTSr7f0yplqV+Ll1fbikmRojSkjcPvGxHaVkjUl3C6Snn TAmUC4Twy68JgdHZoyGqBuHlcQjpYG0wYp3ctRE8UHKPDzXnRseCJL8WvOEj2gJzseh2 wBsSVOOR8/nbGtvjHRBRcIuD/G8yxGQTwdxKJaeXelGp8iHf9MfH6Mf6cCjXlnfaZeq3 LssQ== X-Gm-Message-State: ANoB5pkSHBHezMqEI465MnStx7YnJM9KRCFp6WVw2flVLXva9lIx4Gqz 3cxN39fIuR0wQ7d414Ugv1Kw X-Google-Smtp-Source: AA0mqf6mLO+PCP/hLz4RzLO/qKBWBH5saTD6FZRHSdv23lFs82iecpQbnFjLPZdDntZseE5lX6lfOg== X-Received: by 2002:a17:902:aa06:b0:183:7f67:25d7 with SMTP id be6-20020a170902aa0600b001837f6725d7mr31064610plb.164.1669623339852; Mon, 28 Nov 2022 00:15:39 -0800 (PST) Received: from thinkpad ([117.217.177.120]) by smtp.gmail.com with ESMTPSA id w11-20020a170902ca0b00b001868ed86a95sm8085387pld.174.2022.11.28.00.15.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Nov 2022 00:15:37 -0800 (PST) Date: Mon, 28 Nov 2022 13:45:31 +0530 From: Manivannan Sadhasivam To: Thorsten Leemhuis Cc: catalin.marinas@arm.com, will@kernel.org, robin.murphy@arm.com, amit.pundir@linaro.org, andersson@kernel.org, quic_sibis@quicinc.com, sumit.semwal@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Revert "arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()" Message-ID: <20221128081531.GA60329@thinkpad> References: <20221114110329.68413-1-manivannan.sadhasivam@linaro.org> <6a5b523d-711b-d809-06b9-fdada64c9c65@leemhuis.info> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6a5b523d-711b-d809-06b9-fdada64c9c65@leemhuis.info> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 28, 2022 at 06:44:13AM +0100, Thorsten Leemhuis wrote: > On 14.11.22 12:03, Manivannan Sadhasivam wrote: > > This reverts commit c44094eee32f32f175aadc0efcac449d99b1bbf7. > > > > As reported by Amit [1], dropping cache invalidation from > > arch_dma_prep_coherent() triggers a crash on the Qualcomm SM8250 platform > > (most probably on other Qcom platforms too). The reason is, Qcom > > qcom_q6v5_mss driver copies the firmware metadata and shares it with modem > > for validation. The modem has a secure block (XPU) that will trigger a > > whole system crash if the shared memory is accessed by the CPU while modem > > is poking at it. > > [...] > > [1] https://lore.kernel.org/linux-arm-kernel/CAMi1Hd1VBCFhf7+EXWHQWcGy4k=tcyLa7RGiFdprtRnegSG0Mw@mail.gmail.com/ > > > > I have Amit's report on the list of tracked regressions. I also noticed > the proposed change "arm64: dts: qcom: sc8280xp: fix PCIe DMA coherency": > https://lore.kernel.org/all/20221124142501.29314-1-johan+linaro@kernel.org/ > > I have no expertise in this area, but it looked somewhat related to my > eyes, so please allow me to quickly ask: is that related or even > supposed to fix Amit's regression? > The proposed patch doesn't fix the regression reported by Amit. But the patch itself fixes an issue that might be triggered more frequently by c44094eee32f. Thanks, Mani > Ciao, Thorsten -- மணிவண்ணன் சதாசிவம்