On Mon, Jan 18, 2010 at 01:46:30AM +0000, Ben Dooks wrote:
> On Mon, Jan 18, 2010 at 10:34:29AM +0900, Thomas Abraham wrote:
> > Hi Ben,
> >
> > On Mon, Jan 18, 2010 at 10:10 AM, Ben Dooks <ben-linux@xxxxxxxxx> wrote:
> > > On Mon, Jan 18, 2010 at 09:38:17AM +0900, Thomas Abraham wrote:
> > >> The function s3c_set_clksrc should return if the clksrc_clk clock has
> > >> only one possible parent clock.
> > >
> > > Does this actually relate to a real bug or is this something that you've
> > > come across whilst reading the code?
> >
> > This is required in cases where a clock has a divider but no mux. In
> > s3c_register_clksrc function, after the default set of clock
> > operations are assigned, the parent clock set function s3c_set_clksrc
> > is called. For clocks that do not have mux, the call to s3c_set_clksrc
> > is incorrect.
>
> If you have a look at s3c_set_clksrc() , you will find it already
> checks to see if clk->reg_src.reg is set. It also doesn't call the
> setparent directly either, as it only needs to set clk->clk.parent
> field before exiting.
>
> 132 u32 clksrc = 0;
> 133
> 134 if (clk->reg_src.reg)
> 135 clksrc = __raw_readl(clk->reg_src.reg);
> 136
> 137 clksrc &= mask;
> 138 clksrc >>= clk->reg_src.shift;
> 139
> 140 if (clksrc > srcs->nr_sources || !srcs->sources[clksrc]) {
> 141 printk(KERN_ERR "%s: bad source %d\n",
> 142 clk->clk.name, clksrc);
> 143 return;
> 144 }
> 145
> 146 clk->clk.parent = srcs->sources[clksrc];
>
> This allows us to do some basic verification that the clksrc's sources
> data is valud (such that srcs->nr_sources at least contains one source
> and that it is not NULL).
>From IRL conversation, it seems the problem is that if we do not
have reg_src.reg set at line 134 then we assume that the clksrc has
a srcs array to check. We should change the regs_src.reg code to
check whether the clk->clk.parent is already set and either return
or print a warnign if it is not set.
> > >
> > > From arch/arm/plat-samnsung/clock-clksrc.c:
> > >
> > > 181 if (!clksrc->reg_div.reg)
> > > 182 clksrc->clk.ops = &clksrc_ops_nodiv;
> > > 183 else if (!clksrc->reg_src.reg)
> > > 184 clksrc->clk.ops = &clksrc_ops_nosrc;
> > > 185 else
> > > 186 clksrc->clk.ops = &clksrc_ops;
> > >
> > > So we change the ops dependant on which register(s) we have availalbe.
> > >
> > >> Signed-of-by: Thomas Abraham <thomas.ab@xxxxxxxxxxx>
> > >> ---
> > >> arch/arm/plat-samsung/clock-clksrc.c | 5 +++--
> > >> 1 files changed, 3 insertions(+), 2 deletions(-)
> > >>
> > >> diff --git a/arch/arm/plat-samsung/clock-clksrc.c b/arch/arm/plat-samsung/clock-clksrc.c
> > >> index 33c633a..80da4c4 100644
> > >> --- a/arch/arm/plat-samsung/clock-clksrc.c
> > >> +++ b/arch/arm/plat-samsung/clock-clksrc.c
> > >> @@ -131,9 +131,10 @@ void __init_or_cpufreq s3c_set_clksrc(struct clksrc_clk *clk, bool announce)
> > >> u32 mask = bit_mask(clk->reg_src.shift, clk->reg_src.size);
> > >> u32 clksrc = 0;
> > >>
> > >> - if (clk->reg_src.reg)
> > >> - clksrc = __raw_readl(clk->reg_src.reg);
> > >> + if (!clk->reg_src.reg)
> > >> + return;
> > >>
> > >> + clksrc = __raw_readl(clk->reg_src.reg);
> > >> clksrc &= mask;
> > >> clksrc >>= clk->reg_src.shift;
> > >>
> > >> --
> > >> 1.6.3.3
> > >>
> > >
> > > --
> > > --
> > > Ben
> > >
> > > Q: What's a light-year?
> > > A: One-third less calories than a regular year.
> > >
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> > > the body of a message to majordomo@xxxxxxxxxxxxxxx
> > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > >
> >
> >
> > Thanks,
> > Thomas.
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> > the body of a message to majordomo@xxxxxxxxxxxxxxx
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> --
> Ben
>
> Q: What's a light-year?
> A: One-third less calories than a regular year.
>
--
--
Ben
Q: What's a light-year?
A: One-third less calories than a regular year.
--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
