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Thu, 26 Jun 2025 05:39:07 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: T5f36973fc3fda5d5 Date: Thu, 26 Jun 2025 11:38:46 +0200 From: "Arnd Bergmann" To: "James Clark" , "Frank Li" Cc: "Vladimir Oltean" , "Mark Brown" , "Vladimir Oltean" , "Larisa Grigore" , "Christoph Hellwig" , linux-spi@vger.kernel.org, imx@lists.linux.dev, linux-kernel@vger.kernel.org Message-Id: In-Reply-To: <6fe9eebc-b050-4b12-a28b-e2f0bcc707e2@linaro.org> References: <20250624-james-nxp-spi-dma-v3-0-e7d574f5f62c@linaro.org> <20250624-james-nxp-spi-dma-v3-4-e7d574f5f62c@linaro.org> <228fc6f7-52c2-48a8-af7e-6f2cfa7b9168@linaro.org> <6fe9eebc-b050-4b12-a28b-e2f0bcc707e2@linaro.org> Subject: Re: [PATCH v3 4/6] spi: spi-fsl-dspi: Use non-coherent memory for DMA Content-Type: text/plain Content-Transfer-Encoding: 7bit On Thu, Jun 26, 2025, at 11:14, James Clark wrote: > On 25/06/2025 4:04 pm, Frank Li wrote: >> >> The cover letter will be lost after patch merge. When someone run git log >> after some year later, they need know why need this change , what purpose ... >> > I somewhat disagree with this. Usually maintainers add a 'Link:' to the > mailing list when applying patches, so the cover letter shouldn't be > lost. And these particular performance test results are short lived, in > several years time other things may have changed. The performance is > related to a specific device and the state of the rest of the kernel at > this time. Additionally, I mentioned that it's the combination of two > commits. In order to put figures on this commit message I would have to > run another set of tests with only this commit and not the one to > increase the buffer size which comes after. I did consider reversing the > order of them to do this, but it wasn't straightforward, and I really > didn't think it was worth the effort when I can just put the figures on > the cover letter. If you submit your changes as a pull request for inclusion, the common solution is to put the cover letter into the signed tag, which then gets used as both the description in 'git request-pull' and in the merge commit. See e.g. commit 5b31d2d81a4b ("spi: sh-msiof: Transfer size improvements and I2S") for how a similar series on another driver shows up in the git log. Arnd