Re: [PATCH v2] ARM: shmobile: Add early debugging support using SCIF(A)

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Geert,

On Wednesday 22 October 2014 19:34:17 Geert Uytterhoeven wrote:
> On Wed, Oct 22, 2014 at 6:08 PM, Wolfram Sang <wsa@the-dreams.de> wrote:
> >> I'm wondering whether this can be fixed in the i2c driver? Does it really
> >> have to enable and disable the clock?
> > 
> > From a power-saving PoV, this makes sense. I assume serial output works
> > again as soon as the regular scif driver takes over? Isn't that a
> 
> Yes it continues fine afterwards.
> With TMU0 in DT, it's enabled again even earlier, as they share the parent.

Would it make sense to have a list of clocks to reference from setup code when 
DEBUG_LL is defined ? It's a bit hackish, but DEBUG_LL is hackish anyway.

> > generic problem of early_printk drivers that they are not refcounted for
> > the clocks?
> 
> Yes.
> 
> BTW, the code in sh_mobile_i2c_init() does this:
> 
>         /* Get clock rate after clock is enabled */
>         clk_prepare_enable(pd->clk);
>         i2c_clk_khz = clk_get_rate(pd->clk) / 1000;
>         clk_disable_unprepare(pd->clk);
> 
> I assume the enable/disable is no longer needed with CCF?

I assume so as well.

-- 
Regards,

Laurent Pinchart