Re: [PATCH 04/11] platform/x86: fujitsu-laptop: simplify set_lcd_level()

Darren Hart
2017-04-04T00:01:06Z

On Thu, Mar 30, 2017 at 12:35:02PM +0200, Michał Kępień wrote:
> acpi_execute_simple_method() takes a method parameter which tells it to
> look for the given method underneath the given handle, so calling
> acpi_get_handle() beforehand is redundant. Replace the call to
> acpi_get_handle() with a call to acpi_execute_simple_method(), thus
> eliminating the need for a local variable storing the handle. Also do
> not assign a default value to status as it has no influence on execution
> flow.
>
> Signed-off-by: Michał Kępień <kernel@kempniu.pl>
> ---
> drivers/platform/x86/fujitsu-laptop.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c
> index 5005400b57bb..b888ba190fb2 100644
> --- a/drivers/platform/x86/fujitsu-laptop.c
> +++ b/drivers/platform/x86/fujitsu-laptop.c
> @@ -358,8 +358,7 @@ static enum led_brightness eco_led_get(struct led_classdev *cdev)
>
> static int set_lcd_level(int level)
> {
> - acpi_status status = AE_OK;
> - acpi_handle handle = NULL;
> + acpi_status status;
> char *method;
>
> switch (use_alt_lcd_levels) {
> @@ -377,16 +376,13 @@ static int set_lcd_level(int level)
> if (level < 0 || level >= fujitsu_bl->max_brightness)
> return -EINVAL;
>
> - status = acpi_get_handle(fujitsu_bl->acpi_handle, method, &handle);
> + status = acpi_execute_simple_method(fujitsu_bl->acpi_handle, method,
> + level);
> if (ACPI_FAILURE(status)) {
> vdbg_printk(FUJLAPTOP_DBG_ERROR, "%s not present\n", method);

So this changes behavior a little bit for debug messages. Previously, this
message only triggered if acpi_get_handle failed, now it will trigger if the
method exists but fails, whereas that was silent previously (see below). I think
printing in either case is fine, but we should adjust the message to reflect the
new code flow.

> return -ENODEV;
> }
>
> - status = acpi_execute_simple_method(handle, NULL, level);
> - if (ACPI_FAILURE(status))
> - return -ENODEV;
> -
> return 0;
> }
>
> --
> 2.12.1
>
>

--
Darren Hart
VMware Open Source Technology Center