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[142.68.80.239]) by smtp.gmail.com with ESMTPSA id dx10-20020a056830486a00b006e2dfee49a6sm459641otb.59.2024.02.13.05.47.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Feb 2024 05:47:27 -0800 (PST) Received: from jgg by wakko with local (Exim 4.95) (envelope-from ) id 1rZt8A-004KWC-HE; Tue, 13 Feb 2024 09:47:26 -0400 Date: Tue, 13 Feb 2024 09:47:26 -0400 From: Jason Gunthorpe To: Will Deacon Cc: Dmitry Baryshkov , Robin Murphy , Joerg Roedel , Rob Clark , linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH] Revert "iommu/arm-smmu: Convert to domain_alloc_paging()" Message-ID: <20240213134726.GK765010@ziepe.ca> References: <20240213-iommu-revert-domain-alloc-v1-1-325ff55dece4@linaro.org> <20240213121257.GI765010@ziepe.ca> <20240213121934.GA28726@willie-the-truck> <20240213125303.GJ765010@ziepe.ca> <20240213125951.GB28844@willie-the-truck> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240213125951.GB28844@willie-the-truck> On Tue, Feb 13, 2024 at 12:59:52PM +0000, Will Deacon wrote: > > The typical kernel standard is to fix bugs in patches and only reach > > for a wholesale revert if the community is struggling with bug > > fixing. Dmitry already tested removing that hunk, Robin explained the > > issue, we understand the bug fix is to remove the > > arm_smmu_init_domain_context() call. Nothing justifies a full scale > > revert. > > I can't say I'm aware of any consensus for how to handle this, to be > completely honest with you. Well, I work in a lot of subsystems and this is a surprise to me and not something I've seen before. Fix the bug, move forward. Reverts are a cultural admission of failure. I use threats of a revert as a hammer to encourage people to pay attention to the bugs. I hardly ever actually revert things. What does reverting their code say to my submitters??? > > I'll send another patch if you want, but it seems like a waste of all > > our time. > > It's a bug fix, of course it's a waste of time! We're talking minutes > though, right? It becomes hard for maintainers to juggle the tress since you have to send the revert to -rc and the fix on top of the rc to next. Again, I will send the patch, just discussing. 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[142.68.80.239]) by smtp.gmail.com with ESMTPSA id dx10-20020a056830486a00b006e2dfee49a6sm459641otb.59.2024.02.13.05.47.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Feb 2024 05:47:27 -0800 (PST) Received: from jgg by wakko with local (Exim 4.95) (envelope-from ) id 1rZt8A-004KWC-HE; Tue, 13 Feb 2024 09:47:26 -0400 Date: Tue, 13 Feb 2024 09:47:26 -0400 From: Jason Gunthorpe To: Will Deacon Cc: Dmitry Baryshkov , Robin Murphy , Joerg Roedel , Rob Clark , linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH] Revert "iommu/arm-smmu: Convert to domain_alloc_paging()" Message-ID: <20240213134726.GK765010@ziepe.ca> References: <20240213-iommu-revert-domain-alloc-v1-1-325ff55dece4@linaro.org> <20240213121257.GI765010@ziepe.ca> <20240213121934.GA28726@willie-the-truck> <20240213125303.GJ765010@ziepe.ca> <20240213125951.GB28844@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240213125951.GB28844@willie-the-truck> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240213_054730_130427_ABC53341 X-CRM114-Status: GOOD ( 17.49 ) 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Feb 13, 2024 at 12:59:52PM +0000, Will Deacon wrote: > > The typical kernel standard is to fix bugs in patches and only reach > > for a wholesale revert if the community is struggling with bug > > fixing. Dmitry already tested removing that hunk, Robin explained the > > issue, we understand the bug fix is to remove the > > arm_smmu_init_domain_context() call. Nothing justifies a full scale > > revert. > > I can't say I'm aware of any consensus for how to handle this, to be > completely honest with you. Well, I work in a lot of subsystems and this is a surprise to me and not something I've seen before. Fix the bug, move forward. Reverts are a cultural admission of failure. I use threats of a revert as a hammer to encourage people to pay attention to the bugs. I hardly ever actually revert things. What does reverting their code say to my submitters??? > > I'll send another patch if you want, but it seems like a waste of all > > our time. > > It's a bug fix, of course it's a waste of time! We're talking minutes > though, right? It becomes hard for maintainers to juggle the tress since you have to send the revert to -rc and the fix on top of the rc to next. Again, I will send the patch, just discussing. Jason _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel