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[216.228.112.22]) by smtp.gmail.com with ESMTPSA id v205sm7268836pfc.110.2020.09.29.17.36.56 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 29 Sep 2020 17:36:57 -0700 (PDT) Date: Tue, 29 Sep 2020 17:31:27 -0700 From: Nicolin Chen To: Dmitry Osipenko Cc: thierry.reding@gmail.com, joro@8bytes.org, vdumpa@nvidia.com, jonathanh@nvidia.com, linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, hch@infradead.org Subject: Re: [PATCH v4 2/2] iommu/tegra-smmu: Expand mutex protection range Message-ID: <20200930003126.GA31332@Asurada-Nvidia> References: <20200929061325.10197-1-nicoleotsuka@gmail.com> <20200929061325.10197-3-nicoleotsuka@gmail.com> <184163e9-01d4-dcc5-0adf-a3d175e56f16@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <184163e9-01d4-dcc5-0adf-a3d175e56f16@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org On Tue, Sep 29, 2020 at 08:42:52PM +0300, Dmitry Osipenko wrote: > 29.09.2020 09:13, Nicolin Chen пишет: > > This is used to protect potential race condition at use_count. > > since probes of client drivers, calling attach_dev(), may run > > concurrently. > > > > Signed-off-by: Nicolin Chen > > --- > > It's always better not to mix success and error code paths in order to > keep code readable, but not a big deal in the case of this particular > patch since the changed code is quite simple. Please try to avoid doing > this in the future patches. > > Also, please note that in general it's better to use locked/unlocked > versions for the functions like it's already done for > tegra_smmu_map/unmap, this will remove the need to maintain lockings in > the code. The code touched by this patch doesn't have complicated code > paths, so it's good enough to me. > > Reviewed-by: Dmitry Osipenko Okay. Thanks for the review!