[PATCH v3 1/3] ARM: dts: imx8m: increase off-on delay on the SD Vcc regulator

sbabic at denx.de sbabic at denx.de
Sat Dec 26 16:54:06 CET 2020


> Some SD Card controller and power circuitry has increased capacitance,
> which keeps the internal logic remains powered after regulator is switch
> off. This is generally the case when card is switched to SD104 mode,
> where a power cycle should be performed. In case if the card internal
> logic remains powered, it causes a subsequent failure of mode
> transition, effectively leading to failed enumeration.
> Introduce a delay of 20 msec in order to provide a possibility for
> internal card circuitry to drain voltages and perform a power cycle
> correctly.
> Similar fix is done in commit c49d0ac38a76 ("ARM: dts: rmobile: Increase
> off-on delay on the SD Vcc regulator") targeted Renesas SOCs.
> Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin at leica-geosystems.com>
> Cc: Stefano Babic <sbabic at denx.de>
Applied to u-boot-imx, master, thanks !

Best regards,
Stefano Babic

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