2019-07-22 02:37:12

by Kelsey

Subject: [PATCH 2/3] ACPI: Remove acpi_has_method() call from scan.c

acpi_evaluate_reference() will return an error if the DEP method
does not exist. Checking if the DEP method exists before the
acpi_evaluate_reference() call is not needed. Remove acpi_has_method()
call to avoid additional work.

Signed-off-by: Kelsey Skunberg <[email protected]>
---
drivers/acpi/scan.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 0e28270b0fd8..4f2b0b481cee 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1803,9 +1803,6 @@ static void acpi_device_dep_initialize(struct acpi_device *adev)

adev->dep_unmet = 0;

- if (!acpi_has_method(adev->handle, "_DEP"))
- return;
-
status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
&dep_devices);
if (ACPI_FAILURE(status)) {
--
2.20.1

2019-07-22 08:39:04

by Rafael J. Wysocki

Subject: Re: [PATCH 2/3] ACPI: Remove acpi_has_method() call from scan.c

On Mon, Jul 22, 2019 at 4:36 AM Kelsey Skunberg
<[email protected]> wrote:
>
> acpi_evaluate_reference() will return an error if the DEP method
> does not exist. Checking if the DEP method exists before the
> acpi_evaluate_reference() call is not needed. Remove acpi_has_method()
> call to avoid additional work.
>
> Signed-off-by: Kelsey Skunberg <[email protected]>
> ---
> drivers/acpi/scan.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 0e28270b0fd8..4f2b0b481cee 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1803,9 +1803,6 @@ static void acpi_device_dep_initialize(struct acpi_device *adev)
>
> adev->dep_unmet = 0;
>
> - if (!acpi_has_method(adev->handle, "_DEP"))
> - return;
> -

As you can see, this just returns.

> status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
> &dep_devices);
> if (ACPI_FAILURE(status)) {

Where this does something more on fallure.

Therefore the code after the change is not equivalent to the code
before it, so the changes is questionable.