[U-Boot] [PATCH] arm_cortexa8: support cache flush to other soc

Wolfgang Denk wd at denx.de
Fri Sep 4 13:06:55 CEST 2009


Dear Kyungmin Park,

In message <9c9fda240909040234m4fdd7466ybb38d0d0618cdf32 at mail.gmail.com> you wrote:
> 
...
> >>  #ifndef CONFIG_L2_OFF
> >> -     /* turn off L2 cache */
> >> -     l2_cache_disable();
> >> -     /* invalidate L2 cache also */
> >> -     v7_flush_dcache_all(get_device_type());
> >> -#endif
> >> -     i = 0;
> >> -     /* mem barrier to sync up things */
> >> -     asm("mcr p15, 0, %0, c7, c10, 4": :"r"(i));
> >> +     if (get_device_type() != 0xC100) {
> >
> > Hmm, what is this "0xC100" ?
>
> Now we got two cpu, s5pc100 and s5pc110. In case of s5pc100 we don't
> need to turn off l2 cache. but s5pc110 needs it.
> So first check the device type, actually cpu type. then determine turn
> off l2 cache or not.

Well, this definitely needs a comment, doesn;t it?

And I really dislike such board-specific parts in common code. If what
you want to check is the CPU type, then isn;t there a more direct way?

And do we need a runtime check here? I think that decision can be made
at compile time, right?


...
> maybe not. now we only tested the smdkc100 but actual use is internal
> board for s5pc100 & s5pc110.

Do you use the very same U-Boot image on both SoCs?

Best regards,

Wolfgang Denk

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