[U-Boot] [PATCH] mmc/dwmmc: remove recursive FIFO threshold setup

[Pantelis Antoniou]

Hi Alexey,

On Nov 27, 2013, at 9:11 AM, Alexey Brodkin wrote:

> Hi Jaehoon,
> 
> On Wed, 2013-11-27 at 14:33 +0900, Jaehoon Chung wrote:
>> Hi, Alexey,
>> 
>> I think good that use the initial fifoth value at register.
>> Then we need not to change the value.
>> But according to my experiment, some SoC needs to change the fifoth value.
>> 
> 
> Ok, so let's leave possibility to set "fifoth" manually (if
> "host->fifoth_val" != 0 then use provided value; else do nothing) on mmc
> controller instantiation.
> 
> Will it work for you?
> 

ATM if no host->fifoth_val value is provided the code will calculate one and write it.
Otherwise it will write the one configured.

> Still I have a couple of questions to you:
> 1. Why there's no example/instance of "host->fifoth_val" setup/usage in
> U-Boot source tree? If there was at least one I would leave
> "host->fifoth_val".
> 

I would guess it's because everyone uses the default setting of 0 which
results in a somewhat sane value.

> 2. How come there's no way to set/modify the register in question in
> Linux kernel? Don't people use Linux kernel on mentioned selected SoCs
> without U-Boot (i.e. "fifoth" gets set by U-Boot before kernel starts)?
> 

That's a good question for the kernel driver devs.

> Regards,
> Alexey

Regards

-- Pantelis