On Wed, May 09, 2012 at 04:08:09, Hilman, Kevin wrote:
> Vaibhav Hiremath <hvaibhav@xxxxxx> writes:
>
> > The function __omap2_set_globals() can be common across all
> > platforms/architectures, even in case of omap4, internally it
> > calls same set of functions as in __omap2_set_globals() function
> > (except for sdrc).
>
> OK so far.
>
> > This patch adds new config flag SOC_HAS_OMAP2_SDRC to handle sdrc,
> > so that we can reuse same function across omap2/3/4...
>
> But what happens when a single kernel is built that has support for an
> SoC with an SDRC (OMAP4) and one that doesn't (AM33xx)?
>
As such Nothing...I looking into this direction while implementing.
In that case, sdrc.c file will be compiled in and execution will jump to
omap2_set_globals_sdrc(). But inside this function, we are already checking
whether the omap2_globals->sdrc and omap2_globals->sms for NULL and then use
it.
And function omap2_sdrc_init() is also depends on machine, so in case of
Am33xx, it won't get into sdrc execution at all. And in case of omap4, it
will.
> In that case this new SOC_HAS_OMAP2_SDRC will be set, and
> set_globals_sdrc() will be called even for the SoCs without SDRC.
>
> So, rather than add a new Kconfig option for this, I would rather see
> you using the existing runtime feature check for the SDRC: omap_has_sdrc()
>
There is NO difference between runtime feature check Vs this patch, refer to the function implementation,
void __init omap2_set_globals_sdrc(struct omap_globals *omap2_globals)
{
if (omap2_globals->sdrc)
omap2_sdrc_base = omap2_globals->sdrc;
if (omap2_globals->sms)
omap2_sms_base = omap2_globals->sms;
}
The initialization happens after checking for NULL, so even if you execute it or not, the variable are set to NULL in case of am33xx.
So I don't find any difference between runtime and this patch.
Thanks,
Vaibhav
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