[PATCH v2 1/9] ARM: S3C24XX: cpufreq-utils: don't write raw values to MPLLCON when using ccf
Tomasz Figa
tomasz.figa at gmail.com
Wed Apr 23 13:55:51 PDT 2014
Hi,
On 23.04.2014 22:42, Sergei Shtylyov wrote:
> Hello.
>
> On 04/23/2014 11:34 PM, Heiko Stübner wrote:
>
>> The s3c24xx cpufreq driver needs to change the mpll speed and was doing
>> this by writing raw values from a translation table into the MPLLCON
>> register.
>
>> Change this to use a regular clk_set_rate call when using the common
>> clock framework and only write the raw value in the samsung_clock case.
>
>> To not needing to create additional infrastructure for this, the mpll
>> clock
>> is requested at the first call to s3c2410_set_fvco().
>
>> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
>> ---
>> arch/arm/mach-s3c24xx/cpufreq-utils.c | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>
>> diff --git a/arch/arm/mach-s3c24xx/cpufreq-utils.c
>> b/arch/arm/mach-s3c24xx/cpufreq-utils.c
>> index 2a0aa56..d5e797b 100644
>> --- a/arch/arm/mach-s3c24xx/cpufreq-utils.c
>> +++ b/arch/arm/mach-s3c24xx/cpufreq-utils.c
> [...]
>> @@ -60,5 +61,18 @@ void s3c2410_cpufreq_setrefresh(struct
>> s3c_cpufreq_config *cfg)
>> */
>> void s3c2410_set_fvco(struct s3c_cpufreq_config *cfg)
>> {
>> +#ifdef CONFIG_SAMSUNG_CLOCK
>> __raw_writel(cfg->pll.driver_data, S3C2410_MPLLCON);
>> +#endif
>> +
>> +#ifdef CONFIG_COMMON_CLK
>> + static struct clk *mpll;
>> +
>> + if (!mpll)
>
> You are testing uninitialized variable. This check wouldn't make
> much sense even if the variable was initialized.
I should probably add that NULL is considered a valid clock handle by
Common Clock Framework.
If there is really no way to pass the clock to this function then
probably a global variable initialized by some code running earlier than
this function could be called would be a better choice.
Anyway, Heiko, thanks for working on this. I'll try to review rest of
the series soon. (I'm attending the ELC next week, though, so I'm not
sure if I find some time then, though.)
Best regards,
Tomasz
More information about the linux-arm-kernel
mailing list