From mboxrd@z Thu Jan 1 00:00:00 1970 From: tomasz.figa@gmail.com (Tomasz Figa) Date: Thu, 31 Jul 2014 20:46:51 +0200 Subject: [PATCH v9 6/6] clk: samsung: remove unused clock aliases and update clock flags In-Reply-To: References: <1406707663-16656-1-git-send-email-thomas.ab@samsung.com> <1406707663-16656-7-git-send-email-thomas.ab@samsung.com> <53DA4F1A.5040604@gmail.com> <53DA8C70.2060009@gmail.com> Message-ID: <53DA8F1B.3010907@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 31.07.2014 20:41, Thomas Abraham wrote: > On Fri, Aug 1, 2014 at 12:05 AM, Tomasz Figa wrote: >> On 31.07.2014 20:24, Thomas Abraham wrote: >>> Hi Tomasz, >>> >>> On Thu, Jul 31, 2014 at 7:43 PM, Tomasz Figa wrote: >>>> On 30.07.2014 10:07, Thomas Abraham wrote: >>>>> With some of the Exynos SoCs switched over to use the generic CPUfreq drivers, >>>>> the unused clock aliases can be removed. In addition to this, the individual >>>>> clock blocks which are now encapsulated with the consolidate CPU clock type >>>>> can now be marked with read-only flags. >>>> >>>> [snip] >>>> >>>>> @@ -1500,6 +1499,7 @@ static void __init exynos4_clk_init(struct device_node *np, >>>>> exynos4_soc == EXYNOS4210 ? "Exynos4210" : "Exynos4x12", >>>>> _get_rate("sclk_apll"), _get_rate("sclk_mpll"), >>>>> _get_rate("sclk_epll"), _get_rate("sclk_vpll"), >>>>> + exynos4_soc == EXYNOS4210 ? _get_rate("armclk") : >>>>> _get_rate("div_core2")); >>>> >>>> I believe "div_core2" should work fine here for all SoCs without the >>>> need for this if. >>> >>> The following patch is a pre-requisite for this patch. >>> http://www.spinics.net/lists/arm-kernel/msg351540.html >>> >>> The rate can be obtained from div_core2 as well but with the cpu clock >>> now registered, the rate can be obtained from the cpu clock instance >>> instead of the div_core2 divider. And when Exynos4412 also add cpu >>> clock instance, the 'if' above will be removed. >>> >>>> >>>>> } >>>>> >>>>> diff --git a/drivers/clk/samsung/clk-exynos5250.c b/drivers/clk/samsung/clk-exynos5250.c >>>>> index e19e365..1d958f1 100644 >>>>> --- a/drivers/clk/samsung/clk-exynos5250.c >>>>> +++ b/drivers/clk/samsung/clk-exynos5250.c >>>> >>>> [snip] >>>> >>>>> @@ -848,6 +851,6 @@ static void __init exynos5250_clk_init(struct device_node *np) >>>>> samsung_clk_of_add_provider(np, ctx); >>>>> >>>>> pr_info("Exynos5250: clock setup completed, armclk=%ld\n", >>>>> - _get_rate("div_arm2")); >>>>> + _get_rate("armclk")); >>>> >>>> Similarly here, no need for this change. >>> >>> Same here. Instead of getting the rate from div_core2 divider block, >>> the cpu clock instance is used to find the rate. I would prefer to use >>> cpu clock here. Is there any reason to prefer div_core2 over the cpu >>> clock instance? >> >> Well, the reason is simple: if you don't need to change something (i.e. >> the change doesn't have any advantages), don't change it. > > The advantage with using cpu clock would be that get_rate can obtain > the cached rate whereas when reading div_core2 rate, the clock tree > will have to be traversed to determine the rate. > This is just one time printk at initialization, so still no real benefits. :) Well anyway, if you really don't want to undo this change, then I guess I can live with it. Best regards, Tomasz