[U-Boot] [PATCH 2/2 v3] FSL/eSDHC: enable the clock to detect the SD card

[Scott Wood]

On 05/18/2012 04:57 AM, Chang-Ming.Huang at freescale.com wrote:
> From: Jerry Huang <Chang-Ming.Huang at freescale.com>
> 
> For FSL low-end processors (VVN2.2), in order to detect the SD card,
> we should enable PEREN, HCKEN and IPGEN to enable the clock.
> Otherwise, after booting the u-boot, and then inserting the SD card,
> the SD card can't be detected.
> For SDHC VVN2.3 IP, these bits are reserved, and SDCLKEN is used.
> And when accessing to these reserved bit, no any impact happened.

Again, have you talked to a hardware designer and confirmed that there's
no impact from setting these bits on chips where they're reserved?  Just
because you don't notice any obvious impact doesn't mean it's totally safe.

-Scott