Re: [PATCH v2 4/6] clk: hi6220: Clock driver support for Hisilicon hi6220 SoC

From: Bintian
Date: Mon Apr 13 2015 - 09:20:11 EST

Hello Paul,

Thank you very much for code review and testing on arm!

On 2015/4/13 19:56, Paul Bolle wrote:
On Mon, 2015-04-13 at 17:17 +0800, Bintian Wang wrote:
--- /dev/null
+++ b/drivers/clk/hisilicon/Kconfig
@@ -0,0 +1,5 @@
+config COMMON_CLK_HI6220
+ tristate "Hi6220 Clock Driver"
+ depends on OF && ARCH_HISI
+ help
+ Build the Hisilicon Hi6220 clock driver based on the common clock framework.

In 5/6 you make arm64's ARCH_HISI (a bool) select COMMON_CLK_HI6220. So
for arm64 this driver will always be built-in.

For arm's ARCH_HISI it's possible to set COMMON_CLK_HI6220 to 'm'.

Setting COMMON_CLK_HI6220 to a bool symbol is a good solution based on
current code base, I will fix it in next version.

--- a/drivers/clk/hisilicon/Makefile
+++ b/drivers/clk/hisilicon/Makefile
@@ -2,8 +2,9 @@
# Hisilicon Clock specific Makefile

-obj-y += clk.o clkgate-separated.o
+obj-y += clk.o clkgate-separated.o clkdivider-hi6220.o

These objects will always be built-in, right?

obj-$(CONFIG_ARCH_HI3xxx) += clk-hi3620.o
obj-$(CONFIG_ARCH_HIP04) += clk-hip04.o
obj-$(CONFIG_ARCH_HIX5HD2) += clk-hix5hd2.o
+obj-$(CONFIG_COMMON_CLK_HI6220) += clk-hi6220.o

If CONFIG_COMMON_CLK_HI6220 is 'm' this will build a module named
clk-hi6220.ko. If I try to do that I get:
$ make -C ../../.. ARCH=arm CROSS_COMPILE=arm-linux-gnu- M=$PWD clk-hi6220.ko
make: Entering directory `[...]'
CC [M] [...]/drivers/clk/hisilicon/clk-hi6220.o
MODPOST 1 modules
WARNING: "hisi_clk_register_gate" [[...]/drivers/clk/hisilicon/clk-hi6220.ko] undefined!
WARNING: "hi6220_clk_register_divider" [[...]/drivers/clk/hisilicon/clk-hi6220.ko] undefined!
WARNING: "hisi_clk_register_mux" [[...]/drivers/clk/hisilicon/clk-hi6220.ko] undefined!
WARNING: "hisi_clk_register_gate_sep" [[...]/drivers/clk/hisilicon/clk-hi6220.ko] undefined!
WARNING: "hisi_clk_register_fixed_factor" [[...]/drivers/clk/hisilicon/clk-hi6220.ko] undefined!
WARNING: "hisi_clk_register_fixed_rate" [[...]/drivers/clk/hisilicon/clk-hi6220.ko] undefined!
WARNING: "hisi_clk_init" [[...]/drivers/clk/hisilicon/clk-hi6220.ko] undefined!
CC [...]/drivers/clk/hisilicon/clk-hi6220.mod.o
LDFINAL [M] [...]/drivers/clk/hisilicon/clk-hi6220.ko
make: Leaving directory `[...]'

That is, I think, because nothing exports these symbols.


There's nothing module specific in this file. And the lack of a
MODULE_LICENSE() macro is also telling. If this was built as a module
loading that module - ignoring the undefined symbols - would taint the

It seems to me that COMMON_CLK_HI6220 is meant to be a bool symbol.
You are right.

Paul Bolle

I wonder what checkpatch had to say about the length of the lines seen
in this patch.

Yes, I ran this script before sending out this patch set, it reports
warnings about "line over 80 characters ", but I find it's easier to
read than shrinking one line to several lines, so just keep it, do I
need to fix it?




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