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@leica-geosystems.com Cc: Stefano Babic sbabic@denx.de
Applied to u-boot-imx, master, thanks !
Best regards, Stefano Babic