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 943D6C433EF for ; Mon, 13 Jun 2022 14:47:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1385787AbiFMOqO (ORCPT ); Mon, 13 Jun 2022 10:46:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385906AbiFMOoB (ORCPT ); Mon, 13 Jun 2022 10:44:01 -0400 Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9650B41CC for ; Mon, 13 Jun 2022 04:51:02 -0700 (PDT) Received: from [192.168.1.103] (31.173.86.159) by msexch01.omp.ru (10.188.4.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.986.14; Mon, 13 Jun 2022 14:50:40 +0300 From: Sergey Shtylyov Subject: Re: [PATCH v2] ata: pata_pxa: handle failure of devm_ioremap() To: Damien Le Moal , Sergei Shtylyov , Li Qiong CC: , , References: <20220612073222.18974-1-liqiong@nfschina.com> <20220612125700.11740-1-liqiong@nfschina.com> <097b7e93-4a85-1b6a-1772-67976f834108@opensource.wdc.com> Organization: Open Mobile Platform Message-ID: <80cc4026-a6bf-255f-69d9-d1c1d390f83e@omp.ru> Date: Mon, 13 Jun 2022 14:50:40 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <097b7e93-4a85-1b6a-1772-67976f834108@opensource.wdc.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [31.173.86.159] X-ClientProxiedBy: msexch01.omp.ru (10.188.4.12) To msexch01.omp.ru (10.188.4.12) X-KSE-ServerInfo: msexch01.omp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 5.9.20, Database issued on: 06/13/2022 11:36:46 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 19 X-KSE-AntiSpam-Info: Lua profiles 171074 [Jun 13 2022] X-KSE-AntiSpam-Info: Version: 5.9.20.0 X-KSE-AntiSpam-Info: Envelope from: s.shtylyov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 489 489 b67d2e276d358fa514f5991440453e6a402e3a26 X-KSE-AntiSpam-Info: {rep_avail} X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: {SMTP from is not routable} X-KSE-AntiSpam-Info: {Found in DNSBL: 31.173.86.159 in (user) b.barracudacentral.org} X-KSE-AntiSpam-Info: {Found in DNSBL: 31.173.86.159 in (user) dbl.spamhaus.org} X-KSE-AntiSpam-Info: 127.0.0.199:7.1.2;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;omp.ru:7.1.1 X-KSE-AntiSpam-Info: ApMailHostAddress: 31.173.86.159 X-KSE-AntiSpam-Info: {DNS response errors} X-KSE-AntiSpam-Info: Rate: 19 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-AntiSpam-Info: Auth:dmarc=temperror header.from=omp.ru;spf=temperror smtp.mailfrom=omp.ru;dkim=none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Heuristic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 06/13/2022 11:39:00 X-KSE-AttachmentFiltering-Interceptor-Info: protection disabled X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 6/13/2022 9:03:00 AM X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On 6/13/22 1:47 AM, Damien Le Moal wrote: >>> As the possible failure of the devm_ioremap(), the return value >>> could be NULL. Therefore it should be better to check it and >>> print error message, return '-ENOMEM' error code. > > This error is very unlikely. So unless you are seeing actual problems in > the field, I do not think it is worth fixing. The error paths should absolutely be fixed. It helps avoid an oops later... >>> >>> Signed-off-by: Li Qiong >>> Reviewed-by: Sergey Shtylyov >>> --- >>> v2: >>> - add driver's name (pata_pxa) to subject. >>> --- >>> drivers/ata/pata_pxa.c | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/drivers/ata/pata_pxa.c b/drivers/ata/pata_pxa.c >>> index 985f42c4fd70..cd1a8f37f920 100644 >>> --- a/drivers/ata/pata_pxa.c >>> +++ b/drivers/ata/pata_pxa.c >>> @@ -228,6 +228,11 @@ static int pxa_ata_probe(struct platform_device *pdev) >>> ap->ioaddr.bmdma_addr = devm_ioremap(&pdev->dev, dma_res->start, >>> resource_size(dma_res)); >> >> Looking again into this driver, this statement doesn't make sense: dma_res >> points to a DMA resource, calling devm_ioremap() on it is just wrong... and > > Yes, having to do an ioremap of an IORESOURCE_DMA resource is rather > unusual. dmaengine_slave_config() should be doing anything that is > required for that resource. > >> 'ap->ioaddr.bmdma_addr' doesn;t seem to be used anyways... > > It is used in lbata-sff.c. Where exactly? To me, it looked like all ata_bmdma_port_ops were overridden by the driver... Even if not so, I don't think such code is correct... > > A much cleaner fix would be to use > devm_platform_get_and_ioremap_resource() or > devm_platform_ioremap_resource() which will also remove the call to > platform_get_resource((). This is an -rc1 material. > But as mentioned above, unless this is fixing an > actual bug in production, I do not think this is worth it. I strongly disagree here. MBR, Sergey