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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id E90C9EB64DA for ; Wed, 19 Jul 2023 09:13:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:CC:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Ia/bRfQ/pgcHzggF9fO1TzEPdjg3BuLzw96stGPgDrE=; b=aD778sd3XH3A56JESlKtjtG5AC GHzEB36qlaPndfB/8Rbr9n3o0fDQj54RRPYXfB6jHFaDspIK/mKHPGLrZ9MWOJfsQePf0xEcskhDo Tza5u3LH4b0KVob6RaQJ4vuIGNbdXCf/rtadrDTcC/dUotQ909BlQAojMAgeUJdNnnGpRX/AaYpEY pD7xPmWgaxaDPTjx6FztcvXwPW9ZKnkULqHJQ6gWZWwg0w1j1SG9CMQYHlSZso1Irmz5mOC8FCpEd YVgNuBncdXd8ueAoiIvzvmVUq8ookZERZ+ot6uDOvKMb9ETJYztHoAhm7W3/mppklwcBsp8ja+24I Miaw9Gwg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qM3FT-006W1J-1Y; Wed, 19 Jul 2023 09:13:31 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qM3FP-006Vys-2j for linux-arm-kernel@lists.infradead.org; Wed, 19 Jul 2023 09:13:30 +0000 Received: from dggpemm500002.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4R5VT71yWZzrRr5; Wed, 19 Jul 2023 17:12:27 +0800 (CST) Received: from [10.174.178.247] (10.174.178.247) by dggpemm500002.china.huawei.com (7.185.36.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 19 Jul 2023 17:13:11 +0800 Subject: Re: [PATCH v3] ACPI/IORT: Remove erroneous id_count check in iort_node_get_rmr_info() To: Shameerali Kolothum Thodi , Lorenzo Pieralisi , Guanghui Feng CC: "sudeep.holla@arm.com" , "rafael@kernel.org" , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "baolin.wang@linux.alibaba.com" , "alikernel-developer@linux.alibaba.com" , "will@kernel.org" , "catalin.marinas@arm.com" References: <1689593625-45213-1-git-send-email-guanghuifeng@linux.alibaba.com> <597f481b0e5149dabe4821ca618af6b3@huawei.com> From: Hanjun Guo Message-ID: <613da2c3-d515-b49c-4ff3-cf94836b2acf@huawei.com> Date: Wed, 19 Jul 2023 17:13:10 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <597f481b0e5149dabe4821ca618af6b3@huawei.com> Content-Language: en-GB X-Originating-IP: [10.174.178.247] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500002.china.huawei.com (7.185.36.229) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230719_021328_289861_B529AA9E X-CRM114-Status: GOOD ( 21.26 ) 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2023/7/18 16:56, Shameerali Kolothum Thodi wrote: >> [+Catalin, Will, Shameer] >> >> On Mon, Jul 17, 2023 at 07:33:45PM +0800, Guanghui Feng wrote: >>> According to the ARM IORT specifications DEN 0049 issue E, >>> the "Number of IDs" field in the ID mapping format reports >>> the number of IDs in the mapping range minus one. >>> >>> In iort_node_get_rmr_info(), we erroneously skip ID mappings >>> whose "Number of IDs" equal to 0, resulting in valid mapping >>> nodes with a single ID to map being skipped, which is wrong. >>> >>> Fix iort_node_get_rmr_info() by removing the bogus id_count >>> check. >>> >>> Fixes: 491cf4a6735a ("ACPI/IORT: Add support to retrieve IORT RMR >> reserved regions") >>> Signed-off-by: Guanghui Feng >>> --- >>> drivers/acpi/arm64/iort.c | 3 --- >>> 1 file changed, 3 deletions(-) >>> >>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c >>> index 3631230..56d8873 100644 >>> --- a/drivers/acpi/arm64/iort.c >>> +++ b/drivers/acpi/arm64/iort.c >>> @@ -1007,9 +1007,6 @@ static void iort_node_get_rmr_info(struct >> acpi_iort_node *node, >>> for (i = 0; i < node->mapping_count; i++, map++) { >>> struct acpi_iort_node *parent; >>> >>> - if (!map->id_count) >>> - continue; >>> - >>> parent = ACPI_ADD_PTR(struct acpi_iort_node, iort_table, >>> map->output_reference); >>> if (parent != iommu) >> Shameer, I know this may look like overkill since the hunk we are >> removing is buggy but can you please test this patch on platforms >> with RMR to make sure we are not triggering regressions by removing >> it (by the specs that's what should be done but current firmware >> is always something to reckon with) ? > Yes, that is a valid fix. Unlikely it will be a problem. Anyway, I have requested > Hanjun to help with the testing as I don't have a test setup with me now. Valid fix for me as well, we had a firmware bug which reported the numbers of ID as 1 when we only have one ID mapping, so remove the check is fine for the old firmware, but to make it sure, we need some test before give it a pass. > > Hanjun, please help. I need some time to get it properly tested on two versions of firmware, and get the test machine properly setup, please allow me give the feedback next week. Thanks Hanjun _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel