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 17798C433FE for ; Tue, 30 Nov 2021 08:54:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239864AbhK3I5u (ORCPT ); Tue, 30 Nov 2021 03:57:50 -0500 Received: from alexa-out-sd-01.qualcomm.com ([199.106.114.38]:36429 "EHLO alexa-out-sd-01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239866AbhK3I5t (ORCPT ); Tue, 30 Nov 2021 03:57:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1638262471; x=1669798471; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=b6zv9kZJc11gN8pWj7yPsaq2KZS1Lo+SslBFVfJXTa8=; b=BXWB+/77d4n4Nsm5pzs7FAW8LuvJzc2pQ/laXcEV2NG2SP1S0Xjy6cxn NByCt+sICHeJUxcmrJ/YG7PHBcPyk3AVrI/3FuzNQI7d/c0u5v3A5Sm8L +Vhfy43Mb+JZRoyt5EeO9GUIegLO1elHRKg0XzCbVm5a8Vqaj7T69NPI8 4=; Received: from unknown (HELO ironmsg01-sd.qualcomm.com) ([10.53.140.141]) by alexa-out-sd-01.qualcomm.com with ESMTP; 30 Nov 2021 00:54:30 -0800 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg01-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Nov 2021 00:54:30 -0800 Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Tue, 30 Nov 2021 00:54:30 -0800 Received: from [10.216.48.240] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.922.19; Tue, 30 Nov 2021 00:54:26 -0800 Message-ID: Date: Tue, 30 Nov 2021 14:24:21 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: [PATCH v2 2/2] irqchip: Add Qualcomm MPM controller driver To: Shawn Guo CC: Marc Zyngier , Thomas Gleixner , "Bjorn Andersson" , Rob Herring , Loic Poulain , , , References: <20211126093529.31661-1-shawn.guo@linaro.org> <20211126093529.31661-3-shawn.guo@linaro.org> <87czmmbu8k.wl-maz@kernel.org> <20211129133308.GB10105@dragon> <87pmqjm1c8.wl-maz@kernel.org> <20211130023151.GD10105@dragon> <2e821841-a921-3fda-9ee6-3d5127653033@quicinc.com> <20211130083143.GF10105@dragon> From: Maulik Shah In-Reply-To: <20211130083143.GF10105@dragon> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Hi, On 11/30/2021 2:01 PM, Shawn Guo wrote: >> This can be converted to read poll_timeout(). This was introduced in >> place of wmb() to make sure writes are completed. > Hmm, in this case, writel() will just do the right thing, as it wraps > wmb() there. Or am I missing something? > > Shawn #define writel(v,c)             ({ __iowmb(); writel_relaxed((v),(c)); }) writel() does not do wmb() after writel_relaxed(), it does before. we need to make sure write is propagated, so wmb() or read  back with timeout need to be kept after writel() is done. Thanks, Maulik