Am 08.02.24 um 03:41 schrieb Kuppuswamy Sathyanarayanan:
On 2/7/24 12:20 PM, Armin Wolf wrote:
The ACPI-WMI specification declares that a WMxx control method takes
3 arguments: instance, method id and argument buffer. This is also
the case even when the underlying WMI method does not have any
input arguments.
It would be better if you include specification version and section
title for reference.
The ACPI-WMI specification is not part of the ACPI specification. It
consists of a single whitepaper published by Microsoft:
https://github.com/microsoft/Windows-driver-samples/blob/main/wmi/wmiacpi/wmi-acpi.htm
The section describing the ACPI control methods is called
"ACPI Control Method Naming Conventions and Functionality for Windows 2000 Instrumentation".
I do not thing that mentioning this in the commit message would be of any use.
So if a WMI driver evaluates a WMI method without passing an input
buffer, ACPICA will log a warning complaining that the third argument
is missing.
I assume it is a compile warning. Can you copy the warning message?
Its not a compiler warning.
The ACPI control method is being evaluated at runtime, so the warning message
will also be generated at runtime (when interpreting the AML bytecode).
Thanks,
Armin Wolf
Prevent this by checking that a input buffer was passed, and return
an error if this was not the case.
Tested on a Asus PRIME B650-Plus.
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
---
With above fixed,
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
drivers/platform/x86/wmi.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 63906fdd0abf..f9e23d491dd9 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -296,7 +296,7 @@ EXPORT_SYMBOL_GPL(wmidev_instance_count);
* @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
* @instance: Instance index
* @method_id: Method ID to call
- * @in: Buffer containing input for the method call
+ * @in: Mandatory buffer containing input for the method call
* @out: Empty buffer to return the method results
*
* Call an ACPI-WMI method, the caller must free @out.
@@ -326,7 +326,7 @@ EXPORT_SYMBOL_GPL(wmi_evaluate_method);
* @wdev: A wmi bus device from a driver
* @instance: Instance index
* @method_id: Method ID to call
- * @in: Buffer containing input for the method call
+ * @in: Mandatory buffer containing input for the method call
* @out: Empty buffer to return the method results
*
* Call an ACPI-WMI method, the caller must free @out.
@@ -347,26 +347,25 @@ acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 met
block = &wblock->gblock;
handle = wblock->acpi_device->handle;
+ if (!in)
+ return AE_BAD_DATA;
+
if (!(block->flags & ACPI_WMI_METHOD))
return AE_BAD_DATA;
if (block->instance_count <= instance)
return AE_BAD_PARAMETER;
- input.count = 2;
+ input.count = 3;
input.pointer = params;
+
params[0].type = ACPI_TYPE_INTEGER;
params[0].integer.value = instance;
params[1].type = ACPI_TYPE_INTEGER;
params[1].integer.value = method_id;
-
- if (in) {
- input.count = 3;
-
- params[2].type = get_param_acpi_type(wblock);
- params[2].buffer.length = in->length;
- params[2].buffer.pointer = in->pointer;
- }
+ params[2].type = get_param_acpi_type(wblock);
+ params[2].buffer.length = in->length;
+ params[2].buffer.pointer = in->pointer;
get_acpi_method_name(wblock, 'M', method);
--
2.39.2
