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bb89601282
imx93 pad integrate has one issue, refer to ERR052021: ERR052021 uSDHC: Sometimes uSDHC does not work under VDD_SOC low drive mode and nominal mode Description: uSDHC PADs have one integration issue. When CMD/DATA lines direction change from output to input, uSDHC controller begin sampling, the integration issue will make input enable signal from uSDHC propagated to the PAD with a long delay, thus the new input value on the pad comes to uSDHC lately. The uSDHC sampled the old input value and the sampling result is wrong. Workaround: Set uSDHC CMD/DATA PADs iomux register SION bit to 1, then PADs will propagate input to uSDHC with no delay, so correct value is sampled. This issue will wrongly trigger the start bit when sample the USDHC command response, cause the USDHC trigger command CRC/index/endbit error, which will finally impact the tuning pass window, espically will impact the standard tuning logic, and can't find a correct delay cell to get the best timing. Signed-off-by: Haibo Chen <haibo.chen@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Linux kernel
============
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