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 82246C0502E for ; Sat, 27 Aug 2022 09:42:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234043AbiH0Jmd (ORCPT ); Sat, 27 Aug 2022 05:42:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232646AbiH0Jmb (ORCPT ); Sat, 27 Aug 2022 05:42:31 -0400 Received: from mail-oo1-xc30.google.com (mail-oo1-xc30.google.com [IPv6:2607:f8b0:4864:20::c30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1694396FF8; Sat, 27 Aug 2022 02:42:31 -0700 (PDT) Received: by mail-oo1-xc30.google.com with SMTP id p48-20020a4a95f3000000b0044b0f5a8d17so675460ooi.0; Sat, 27 Aug 2022 02:42:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc; bh=rqXbDU0e1tN4j5qNVRfAuljmb4yEN9erSBSwCMYT9p4=; b=ClMxVp+vwHXZuCvXg9uAgklzyD8SdlevrrCBTD0YEFrqGGPCOFJzyyISmPpuF27pqp Gg0k14dwf5ws2PSjWdiX8zm1tWEgYY9jMXoQcCFeSPe3aHRLDD1DK0ubptEBXt4e5AWX /ycS1tINPMWt6jWr43uERP3X097Qh/yRP61wdaUbDXIHSGc5OF1pqZpJ4Dll0iY/ukrO 8P+J+gHcWofpYWC938hYiu0BNJ08y/EQIqch3XMlEIZqHjBo6aweYjCNjYIexL5VsNMK cURhZ7AUK1um6itvwquxmRr2FiIf0NFIy1q8ehRKrOx7UKgnat9IuEPRyFlqxKipye9A N6Bw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc; bh=rqXbDU0e1tN4j5qNVRfAuljmb4yEN9erSBSwCMYT9p4=; b=zqrG5fhYw4LnYDg+4LsiNKnd1AcllaA76lemVygAcbE5WZPfO7L+QECRsQrg3bQTAQ Pr8dCLRZalT2uVdxmSprW2xhwqcHWIRPZHH01Uh6YtPdBeHfdXNrF4z8hpNx9BjCRq9g QngTV5H3EztQ7hpU6ehKTwpBNhIyqydlSn8koF95HCGbPLuBdVTxCs+bNgYp5NmREDLP 5+odBhJK/45zjduCp7XRTYgSC5ugWG6q6e20dGu2jUyiqWK7vem5mdwUX7Lu4676kKC0 YtZhKsVkSqpKcbltbhJvBUsIhIntz90OyBDAMERZ/6dcV02VAmlmMHw+y8AHaCuhieR/ Vo7g== X-Gm-Message-State: ACgBeo0SKYAeK/Av2bH5+TJcrOnJo0De7lEhuTHNJqu5+BkzsA+kkddM mvXa2eW4+JQPLNao5Za6s0mVQNzYvsK9MVhsNF0k7kje9Koi6g== X-Google-Smtp-Source: AA6agR7B9I6t4g5X3YmiBGfhO1RGQqgDYZA8IWaaMnL2zcRgHEWvokmIMvvJe4Yh7jD5YugeIEhqZwAPSP+Qq9w1Y58= X-Received: by 2002:a4a:d154:0:b0:449:681b:3e76 with SMTP id o20-20020a4ad154000000b00449681b3e76mr2496123oor.47.1661593350486; Sat, 27 Aug 2022 02:42:30 -0700 (PDT) MIME-Version: 1.0 References: <20220822141110.17199-1-91tuocao@gmail.com> In-Reply-To: From: tuo cao <91tuocao@gmail.com> Date: Sat, 27 Aug 2022 17:42:19 +0800 Message-ID: Subject: Re: [RESEND] serial: 8250_bcm7271: move spin_lock_irqsave to spin_lock in interrupt handler To: Greg KH Cc: alcooperx@gmail.com, bcm-kernel-feedback-list@broadcom.com, jirislaby@kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org No, whether it's spin_lock_irqsave() or spin_lock(), the security is the same. Since this commit:e58aa3d2d0cc01ad8d6f7f640a0670433f794922, interrupt nesting is disabled, which means interrupts has disabled in the interrupt handlers. So, it is unnecessary to call spin_lock_irqsave in a interrupt handler. And it takes less time obviously to use spin_lock()=EF=BC=8Cso I think this change is needed. Finally, I'm sorry I lacked real hardware to verify it and can't provide changelog text. Thanks. Greg KH =E4=BA=8E2022=E5=B9=B48=E6=9C=8822=E6= =97=A5=E5=91=A8=E4=B8=80 22:25=E5=86=99=E9=81=93=EF=BC=9A > > On Mon, Aug 22, 2022 at 10:11:10PM +0800, Tuo Cao wrote: > > it is unnecessary to call spin_lock_irqsave in a interrupt handler. > > Yes, but it is safer to do so, right? > > Why is this change needed? > > Did you test it on real hardware to verify it works? > > We need a lot more information in the changelog text before being able > to accept this. > > thanks, > > greg k-h