[PATCH 01/11] ARM: omap: clk: add clk_prepare and clk_unprepare

Rajendra Nayak
2012-06-25T05:36:04Z

On Friday 22 June 2012 11:12 PM, Pankaj Jangra wrote:
>> diff --git a/arch/arm/mach-omap2/display.c b/arch/arm/mach-omap2/display.c
>> > index 5fb47a1..e5f8e48 100644
>> > --- a/arch/arm/mach-omap2/display.c
>> > +++ b/arch/arm/mach-omap2/display.c
>> > @@ -471,7 +471,7 @@ int omap_dss_reset(struct omap_hwmod *oh)
>> >
>> > for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i> 0; i--, oc++)
>> > if (oc->_clk)
>> > - clk_enable(oc->_clk);
>> > + clk_prepare_enable(oc->_clk);
>> >
>> > dispc_disable_outputs();
>> >
>> > @@ -498,7 +498,7 @@ int omap_dss_reset(struct omap_hwmod *oh)
>> >
>> > for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i> 0; i--, oc++)
>> > if (oc->_clk)
>> > - clk_disable(oc->_clk);
>> > + clk_disable_unprepare(oc->_clk);
>> >
> Just a doubt. Isn't it the same clocks you are preparing in omap_hwmod.c ?

Yes, but different users can and should prepare and enable clocks
independently, and hence the framework does usecounting to keep track.

>
>> > r = (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0;
>> >
> d> diff --git a/arch/arm/mach-omap2/omap_hwmod.c
> b/arch/arm/mach-omap2/omap_hwmod.c
>> > index bf86f7e..2746bce 100644
>> > --- a/arch/arm/mach-omap2/omap_hwmod.c
>> > +++ b/arch/arm/mach-omap2/omap_hwmod.c
>> > @@ -608,6 +608,7 @@ static int _init_main_clk(struct omap_hwmod *oh)
>> > oh->name, oh->main_clk);
>> > return -EINVAL;
>> > }
>> > + clk_prepare(oh->_clk);
>> >
>> > if (!oh->_clk->clkdm)
>> > pr_warning("omap_hwmod: %s: missing clockdomain for %s.\n",
>> > @@ -644,6 +645,7 @@ static int _init_interface_clks(struct omap_hwmod *oh)
>> > oh->name, os->clk);
>> > ret = -EINVAL;
>> > }
>> > + clk_prepare(os->_clk);
>> > os->_clk = c;
> You should do clk_prepare() after os->_clk = c statement. Otherwise
> you are operating on a uninitialized structure pointer.

yes, that was really stupid of me :(. Thanks for catching this.

>> > }
>> >
>> > @@ -671,6 +673,7 @@ static int _init_opt_clks(struct omap_hwmod *oh)
>> > oh->name, oc->clk);
>> > ret = -EINVAL;
>> > }
>> > + clk_prepare(oc->_clk);
> Same here. You are preparing the uninitialized clk structure.

Thanks, will fix.

>