Messages in this thread | | | Subject | Re: [PATCH] clk: <linux/clk.h>: correct clk_get_parent() documentation | From | Randy Dunlap <> | Date | Tue, 27 Apr 2021 10:07:04 -0700 |
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On 4/27/21 2:38 AM, Russell King - ARM Linux admin wrote: > On Mon, Apr 26, 2021 at 08:13:42PM -0700, Randy Dunlap wrote: >> Make the kernel-doc return value agree with both the stub implementation >> in <linux/clk.h> and the non-stub function in drivers/clk/clk.c. >> >> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> >> Cc: Russell King <linux@armlinux.org.uk> >> Cc: linux-clk@vger.kernel.org >> --- >> There are several drivers that call clk_get_parent() and use its >> return value as though it returns an ERR_PTR(). I am working on a >> patch series to fix those. > > The whole premise of the CLK API is that: > > - clk values that IS_ERR() returns true are errors > - clk values that IS_ERR() returns false are valid > > and that is that - nice, simple, easy to understand. So the > documentation is correct. If clk_get_parent() needs to return an > error, it does so by returning an error-pointer, not by returning > NULL.
Hm, so the 6 drivers that do this are OK then, if clk_get_parent() returns NULL?
parent = clk_get_parent(clk); if (IS_ERR(parent)) { dev_err(cpu_dev, "Cannot get parent clock for CPU0\n"); clk_put(clk); return PTR_ERR(parent); }
/* Get parent CPU frequency */ base_frequency = clk_get_rate(parent);
boom?
-- ~Randy
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