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=-5.3 required=3.0 tests=BAYES_00, 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 4843EC07E9C for ; Tue, 6 Jul 2021 10:26:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EDFC619AD for ; Tue, 6 Jul 2021 10:26:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231281AbhGFK3X (ORCPT ); Tue, 6 Jul 2021 06:29:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:53186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231208AbhGFK3X (ORCPT ); Tue, 6 Jul 2021 06:29:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5724B619A9; Tue, 6 Jul 2021 10:26:43 +0000 (UTC) Date: Tue, 6 Jul 2021 11:26:35 +0100 From: Catalin Marinas To: Yassine Oudjana Cc: "will@kernel.org" , "ardb@kernel.org" , "arnd@arndb.de" , "kernel-team@android.com" , "linux-arm-kernel@lists.infradead.org" , "mark.rutland@arm.com" , "vincent.whitchurch@axis.com" , "linux-arm-msm@vger.kernel.org" Subject: Re: [PATCH] arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES) Message-ID: <20210706102634.GB24903@arm.com> References: <20210527124356.22367-1-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Tue, Jul 06, 2021 at 09:26:59AM +0000, Yassine Oudjana wrote: > In-Reply-To: <20210527124356.22367-1-will@kernel.org> > > Reduce ARCH_DMA_MINALIGN to 64 bytes and allow the warning/taint to > > indicate if there are machines that unknowingly rely on this. > > The warning is being triggered on Qualcomm MSM8996, as well as the out-of-spec taint: Is this booting with ACPI or DT? > ------------[ cut here ]------------ > rtc-pm8xxx 400f000.qcom,spmi:pmic@0:rtc@6000: ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (64 < 128) > WARNING: CPU: 0 PID: 1 at arch/arm64/mm/dma-mapping.c:45 arch_setup_dma_ops+0xf8/0x10c [...] > This warning is triggered with nearly every driver probe, not only rtc-pm8xxx. I have a suspicion none of the reported devices actually do any DMA, so in practice it should be safe but we need to figure out why arch_setup_dma_ops() gets called. -- Catalin 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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 14D80C07E96 for ; Tue, 6 Jul 2021 10:28:47 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D06AF61958 for ; Tue, 6 Jul 2021 10:28:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D06AF61958 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com 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=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=yND/t/u1qCj53gCBQaAIB/eb11CE7JUVOXbVdvkuRHM=; b=3pxeVpForSPfv4 +YUF70S/zF0tuhWKQ/ut5i4QVcICOmH+5+nZqLlt/I5daUZyvBmdrSE+P7FlcemppozrHNjySjVI7 xGCwOZCESlhKUvNiOGcp9vIndcKuDen7HVFawFOaKlFhFYmhgqx1RobVnwts6nRmdn42AuWbdux6l q28Sffj6x3Qez9jTBFgKHn3n5QI+O1sJKWjsdsEGXyxPoQiVtgIvgZm95CwJnNa5GixKvTZS3SVDi g+iM4fVwf2azO9c4AXIz4NX9g9QsMgjV1DOIQlm67jeRi0s/yF0bRyJinYhlmB0zwpbyE3VrhnQqw VFV2Abhtv25z0skW2sLg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m0iHw-00B1ss-Kh; Tue, 06 Jul 2021 10:26:48 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m0iHt-00B1sU-4r for linux-arm-kernel@lists.infradead.org; Tue, 06 Jul 2021 10:26:46 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5724B619A9; Tue, 6 Jul 2021 10:26:43 +0000 (UTC) Date: Tue, 6 Jul 2021 11:26:35 +0100 From: Catalin Marinas To: Yassine Oudjana Cc: "will@kernel.org" , "ardb@kernel.org" , "arnd@arndb.de" , "kernel-team@android.com" , "linux-arm-kernel@lists.infradead.org" , "mark.rutland@arm.com" , "vincent.whitchurch@axis.com" , "linux-arm-msm@vger.kernel.org" Subject: Re: [PATCH] arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES) Message-ID: <20210706102634.GB24903@arm.com> References: <20210527124356.22367-1-will@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210706_032645_246088_3A8953D9 X-CRM114-Status: GOOD ( 13.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 06, 2021 at 09:26:59AM +0000, Yassine Oudjana wrote: > In-Reply-To: <20210527124356.22367-1-will@kernel.org> > > Reduce ARCH_DMA_MINALIGN to 64 bytes and allow the warning/taint to > > indicate if there are machines that unknowingly rely on this. > > The warning is being triggered on Qualcomm MSM8996, as well as the out-of-spec taint: Is this booting with ACPI or DT? > ------------[ cut here ]------------ > rtc-pm8xxx 400f000.qcom,spmi:pmic@0:rtc@6000: ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (64 < 128) > WARNING: CPU: 0 PID: 1 at arch/arm64/mm/dma-mapping.c:45 arch_setup_dma_ops+0xf8/0x10c [...] > This warning is triggered with nearly every driver probe, not only rtc-pm8xxx. I have a suspicion none of the reported devices actually do any DMA, so in practice it should be safe but we need to figure out why arch_setup_dma_ops() gets called. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel