Subject: Re: [PATCH V4 5/5] clk: imx8qxp: Support building i.MX8QXP clock
driver as module

On Thu, Jul 2, 2020 at 11:55 AM Anson Huang [off-list ref]
wrote:
[...]

quoted

quoted

quoted

+{
+       return platform_driver_register(&imx8qxp_lpcg_clk_driver);
+}
+device_initcall(imx8qxp_lpcg_clk_init);

Any reason to change to device_initcall which looks a bit strange?
Is it because the following line?
+obj-$(CONFIG_MXC_CLK_SCU) += clk-imx-scu.o clk-imx-lpcg-scu.o
But it looks to me they're still two modules. Aren't they?

It is suggested by Arnd to NOT use builtin_platform_driver(), in order
to support module unload, although the clock driver normally does NOT
support remove, but it is better to follow the right way.

By expanding builtin_platform_driver() marcro, you will find your patch is
exactly doing the same thing as buildin_platform_driver() which obivously is
unneccesary.

#define builtin_platform_driver(__platform_driver) \
        builtin_driver(__platform_driver, platform_driver_register) #define
builtin_driver(__driver, __register, ...) \

static int __init __driver##_init(void) \ { \
        return __register(&(__driver) , ##__VA_ARGS__); \ } \
device_initcall(__driver##_init);

If we want to support unload, we need a .remove() callback as current clocks
are not allocated by devm_().
If don't support,  we probably can use builtin_platform_driver() first and
switch to module_platform_driver() in the future once the driver supports
release resource properly.

Yes, that is why I use the device_initcall() to make it exactly same as builtin_driver(),
and also yes that i.MX clock driver does NOT support module unload, so .remove()
is NOT implemented, I am fine with either way, just try to address Arnd's comment.

Hi, Arnd
	What do you think? Do you agree to keep using the builtin_driver()?

Thanks,
Anson
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