[U-Boot] [PATCH] mmc: it's safe to ignore mmc_send_if_cond() return value

[Ilya Yanok]

Hi Alfred,

alfred steele wrote:
>> We don't have clocks API in U-Boot. You need to enable the clock by
>> setting appropriate bit in the clocks control register manually.
>>     
> Why do i have to touch the CCM? IIRC, Can't it be controlled with the
> STR_STP_CLOCK (bit 0).  When i read the CCM using md.l it shows the
> Clock output set to IPG_CLK already which is an input  the internally
> generated MMC_SD_CLK. Please correct me if am wrong.
>   

Well, I can't really give you some definite answers here... Now I'm
concentrated on mx27 and we have separate bits for controlling SDHC
clocks here (they are not in CCM but in PCCR0)...
Just make sure that you have all needed clocks enabled.

>  Hmm... I didn't touch any SPBA setting on mx27... But it may be needed
>   
>> on mx31... Look at the spba_take_ownership() code and if it does
>> somethings with registers try setting registers to the same values from
>> your board code.
>>     
> I have it set in my code, it does not make any difference .  I think
> it makes sense only for interrupt and dma transfers although i am not
> sure.
> Another thing i wasn't sure of was as to where is the endianness and
> bus width for the host controller getting set in the mx27 code?
>   

I don't think that can be an issue.

>> That's all I can tell you: check pins configuration, check if the clocks
>> are enabled and if mx31 has more than one MMC controller check that you
>> are trying to talk to the one with card connector (or just try other
>> choices).
>>     
> Thanks Ilya. Will try.
>   

Trying another controller may be a good option (just don't forget that
you need to configure different pins). I faced that problem myself: I
was trying to find the card at SDHC0 but it turned out that it's
connected to SDHC1... And AFAIR in my case I didn't get answer for
OP_COND too (actually not getting answer for OP_COND means that there is
no card).

Regards, Ilya.