[U-Boot] socfpga: initialize MMC

Wolfgang Denk wd at denx.de
Thu Jul 17 14:01:20 CEST 2014


Dear Chin Liang,

In message <1405594852.2088.8.camel at clsee-VirtualBox.altera.com> you wrote:
> 
> > > > +	add_dwmci(host, host->bus_hz, host->bus_hz);
> > > 
> > > Is there a free(host) anywhere?
> 
> Actually the host will be referred throughout the code execution when
> SDMMC access is required. Hence, we can only call the free when exit
> which deems not needed then.

I have to admit that I have hard times trying to understand the
concept of behind this code.

1) The new patches add  altera_dwmmc_init()  - but is this not
   basically a verbatim copy of  socfpga_dwmmc_init()  which is
   alreday in mainline?

   Except that the new patches use hardcoded constants (which is BAD)
   where the current mainline code uses #defines:

   altera_dwmmc_init():

	host->bus_hz = 400000;

   socfpga_dwmmc_init():

	host->bus_hz = CONFIG_SOCFPGA_DWMMC_BUS_HZ;

2) Is it really necessary to always and unconditionally initialyze
   the MMC subsystem, even in nobody will ever use any MMC commands in
   U-Boot?  The rule is that we only initialize hardwar when we
   actually use them inside of U-Boot, i. e. if any commands are
   executed that access such hardware?

   [Ok, this seems to be a generic problem, not specific you your
   patch set.]


Best regards,

Wolfgang Denk

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