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 C9DB5C433F5 for ; Mon, 14 Feb 2022 12:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353153AbiBNMcg (ORCPT ); Mon, 14 Feb 2022 07:32:36 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:59140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231529AbiBNMcg (ORCPT ); Mon, 14 Feb 2022 07:32:36 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B76274A3C5 for ; Mon, 14 Feb 2022 04:32:27 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6694C1396; Mon, 14 Feb 2022 04:32:27 -0800 (PST) Received: from [10.57.70.89] (unknown [10.57.70.89]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 572EB3F718; Mon, 14 Feb 2022 04:32:26 -0800 (PST) Message-ID: Date: Mon, 14 Feb 2022 12:32:21 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Thunderbird/91.6.0 Subject: Re: [PATCH] iommu/ipmmu-vmsa: Check for error num after setting mask Content-Language: en-GB To: Joerg Roedel , Jiasheng Jiang Cc: will@kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Nikita Yushchenko , Laurent Pinchart References: <20220106024302.2574180-1-jiasheng@iscas.ac.cn> From: Robin Murphy In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-02-14 11:43, Joerg Roedel wrote: > Adding more potential reviewers. > > On Thu, Jan 06, 2022 at 10:43:02AM +0800, Jiasheng Jiang wrote: >> Because of the possible failure of the dma_supported(), the >> dma_set_mask_and_coherent() may return error num. >> Therefore, it should be better to check it and return the error if >> fails. In this particular case it cannot fail on any system the driver actually runs on - it's a platform device so the dma_mask pointer is always initialised, then dma_direct_supported() on arm64 will always return true for any mask wider than 32 bits, while arm_dma_supported() will also always pass since a 32-bit system cannot have memory above 40 bits either. There's no great harm in adding the check for the sake of consistency, I guess, but it's purely cosmetic and not fixing anything. Thanks, Robin. >> Fixes: 1c894225bf5b ("iommu/ipmmu-vmsa: IPMMU device is 40-bit bus master") >> Signed-off-by: Jiasheng Jiang >> --- >> drivers/iommu/ipmmu-vmsa.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c >> index aaa6a4d59057..7df5da44a004 100644 >> --- a/drivers/iommu/ipmmu-vmsa.c >> +++ b/drivers/iommu/ipmmu-vmsa.c >> @@ -1003,7 +1003,9 @@ static int ipmmu_probe(struct platform_device *pdev) >> bitmap_zero(mmu->ctx, IPMMU_CTX_MAX); >> mmu->features = of_device_get_match_data(&pdev->dev); >> memset(mmu->utlb_ctx, IPMMU_CTX_INVALID, mmu->features->num_utlbs); >> - dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40)); >> + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40)); >> + if (ret) >> + return ret; >> >> /* Map I/O memory and request IRQ. */ >> res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> -- >> 2.25.1