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Thu, 12 Sep 2024 08:08:59 +0200 Date: Thu, 12 Sep 2024 08:08:59 +0200 From: Johan Hovold To: manivannan.sadhasivam@linaro.org Cc: Richard Zhu , Lucas Stach , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Jingoo Han , Chuanhua Lei , Marek Vasut , Yoshihiro Shimoda , Pratyush Anand , Thierry Reding , Jonathan Hunter , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org, abel.vesa@linaro.org, johan+linaro@kernel.org, Shashank Babu Chinta Venkata , linux-tegra@vger.kernel.org Subject: Re: [PATCH v7 3/4] PCI: qcom: Add equalization settings for 16.0 GT/s Message-ID: References: <20240911-pci-qcom-gen4-stability-v7-0-743f5c1fd027@linaro.org> <20240911-pci-qcom-gen4-stability-v7-3-743f5c1fd027@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240911-pci-qcom-gen4-stability-v7-3-743f5c1fd027@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240912_070847_925138_0B3E5B8F X-CRM114-Status: GOOD ( 10.94 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Sep 11, 2024 at 08:56:28PM +0530, Manivannan Sadhasivam via B4 Relay wrote: > From: Shashank Babu Chinta Venkata > > During high data transmission rates such as 16.0 GT/s, there is an > increased risk of signal loss due to poor channel quality and interference. > This can impact receiver's ability to capture signals accurately. Hence, > signal compensation is achieved through appropriate lane equalization > settings at both transmitter and receiver. This will result in increased > PCIe signal strength. > > While at it, let's also modify the pcie-tegra194 driver to make use of the > common GEN3_EQ_CONTROL_OFF definitions in pcie-designware.h. > > Signed-off-by: Shashank Babu Chinta Venkata > Reviewed-by: Manivannan Sadhasivam > [mani: dropped the code refactoring and minor changes] > Tested-by: Johan Hovold > Signed-off-by: Manivannan Sadhasivam Reviewed-by: Johan Hovold