Hi, On Mon, Oct 14, 2013 at 11:56 PM, Kyungmin Park <kmpark@xxxxxxxxxxxxx> wrote: > On Tue, Oct 15, 2013 at 3:23 PM, Naveen Krishna Chatradhi > <ch.naveen@xxxxxxxxxxx> wrote: >> For Exynos4 and Exynos5 SoCs from Samsung the i2c clock is based >> on a fixed 66 MHz peripheral clock, and therefore is completely >> independent of the cpu frequency. >> Thus, registering for a CPU freq notifier is very wasteful. >> >> This patch modifes the code such that, i2c bus registers to >> cpu_freq_transition only if CONFIG_CPU_FREQ_S3C24XX is enabled. >> >> This change should save a bunch of cpufreq transitions calls >> which does not apply to exynos SoCs. >> >> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx> > Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> >> --- >> Changes since v1: >> Use CONFIG_CPU_FREQ_S3C24XX instead of (CONFIG_CPU_FREQ & !CONFIG_EXYNOS) >> As commented by Tomasz >> >> drivers/i2c/busses/i2c-s3c2410.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) Looks great to me. Thank you for the suggestions Tomasz, as always. Reviewed-by: Doug Anderson <dianders@xxxxxxxxxxxx> We need to come up with a solution for the CPU_FREQ stuff in s3c2410_wdt too. We could use a similar solution but since the CPU_FREQ stuff in s3c2410_wdt is more than just an optimization it means that it's not good if S3C24XX is included in a multiplatform kernel. (For the watchdog it's more than just an optimization since every frequency transition actually pets the watchdog, making it useless when you transition several times per second). -Doug -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
