On Fri, Aug 1, 2014 at 12:16 AM, Tomasz Figa [off-list ref] wrote:

On 31.07.2014 20:41, Thomas Abraham wrote:

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On Fri, Aug 1, 2014 at 12:05 AM, Tomasz Figa [off-list ref] wrote:

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On 31.07.2014 20:24, Thomas Abraham wrote:

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Hi Tomasz,

On Thu, Jul 31, 2014 at 7:43 PM, Tomasz Figa [off-list ref] wrote:

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On 30.07.2014 10:07, Thomas Abraham wrote:

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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]

quoted

@@ -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.

quoted

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 }

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]

quoted

@@ -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.

Thanks Tomasz. Probably, I would just use cpu clock for now.

Best regards,
Tomasz