Re: [PATCH v5 1/7] cpufreq: amd-pstate: cleanup the unused and duplicated headers declaration

From: Punit Agrawal
Date: Mon Aug 15 2022 - 11:04:48 EST


Hi Perry,

Perry Yuan <Perry.Yuan@xxxxxxx> writes:

> Cleanup the headers declaration which are not used
> actually and some duplicated declaration which is declarated in some
> other headers already, it will help to simplify the header part.

We usually don't get rid of indirectly included headers as long as
definitions from header are used in the code. This avoids problems if
for some reason the included header gets dropped - it'll leave the code
in an uncompilable state.

More below.

>
> Reviewed-by: Huang Rui <ray.huang@xxxxxxx>
> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Signed-off-by: Perry Yuan <Perry.Yuan@xxxxxxx>
> ---
> drivers/cpufreq/amd-pstate.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 9ac75c1cde9c..19a078e232dd 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -31,19 +31,14 @@
> #include <linux/compiler.h>
> #include <linux/dmi.h>
> #include <linux/slab.h>
> -#include <linux/acpi.h>
> #include <linux/io.h>
> #include <linux/delay.h>
> #include <linux/uaccess.h>
> #include <linux/static_call.h>
>
> -#include <acpi/processor.h>
> #include <acpi/cppc_acpi.h>
>
> #include <asm/msr.h>
> -#include <asm/processor.h>

On a quick scan, I noticed that "boot_cpu_data" and "boot_cpu_has()" in
the module init function are defined in "asm/processor.h" that is being
removed here. It may compile for now but makes the code more fragile as
explained above.

Please ensure that only the header files that have no definitions used
in this file (amd-pstate.c) are dropped.

> -#include <asm/cpufeature.h>
> -#include <asm/cpu_device_id.h>
> #include "amd-pstate-trace.h"
>
> #define AMD_PSTATE_TRANSITION_LATENCY 0x20000