[PATCH] mmc: Add power stabilization delay in mmc_power_on()

Marek Vasut marek.vasut at mailbox.org
Tue Dec 30 14:37:14 CET 2025


On 12/30/25 11:39 AM, ziniu.wang_1 at nxp.com wrote:
> From: Luke Wang <ziniu.wang_1 at nxp.com>
> 
> After enabling vmmc supply, add 10ms delay to allow voltage to
> stabilize before SD initialization starts. Without this delay,
> some SD cards fail to initialize because the initial clock cycles
> are sent while power is still ramping up.
Details please. Which exact cards ? With which controller/SoC ? Does 
this problem happen on another SoC/controller ?

Without useful details, this is a NAK.


More information about the U-Boot mailing list