Re: [PATCH] Fix returns of some CLK API calls, if !CONFIG_HAVE_CLOCK

From: Russell King - ARM Linux
Date: Tue Apr 25 2017 - 12:31:58 EST


On Tue, Apr 25, 2017 at 02:30:07PM +0200, Thomas Bogendoerfer wrote:
> If CONFIG_HAVE_CLOCK is not set, return values of clk_get(),
> devm_clk_get(), devm_get_clk_from_child(), clk_get_parent()
> and clk_get_sys() are wrong. According to spec these functions
> should either return a pointer to a struct clk or a valid IS_ERR
> condition. NULL is neither, so returning ERR_PTR(-ENODEV) makes
> more sense.

That's wrong. When the clk API is disabled, the expected behaviour is
that drivers will not fail. Returning ERR_PTR(-ENODEV) will cause them
to fail, so will break platforms.

NAK.

> Without this change serial console on SNI RM400 machines (MIPS arch)
> is broken, because sccnxp driver doesn't get a valid clock rate.

So the driver needs to depend on HAVE_CLOCK.

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