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

On Friday 22 June 2012 11:12 PM, Pankaj Jangra wrote:

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diff --git a/arch/arm/mach-omap2/display.c b/arch/arm/mach-omap2/display.c

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 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.

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         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

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 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.

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         }

 @@ -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.