[PATCH v1 1/8] ACPI: bus: Fix handling of _OSC errors in acpi_run_osc()

Rafael J. Wysocki
2025-12-18T20:43:32Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The handling of _OSC errors in acpi_run_osc() is inconsistent.

For example, if OSC_CAPABILITIES_MASK_ERROR is set in the return buffer
and OSC_QUERY_ENABLE is set in the capabilities buffer, all of the
_OSC errors will be ignored even though some of them indicate that
_OSC evaluation has failed. However, if OSC_QUERY_ENABLE is not set in
the capabilities buffer, all _OSC errors will be reported, but the error
value returned by acpi_run_osc() depends on whether or not
OSC_CAPABILITIES_MASK_ERROR is set in the return buffer.

Adress this by making acpi_run_osc() clear OSC_CAPABILITIES_MASK_ERROR
in the return buffer if OSC_QUERY_ENABLE is set in the capabilities
buffer and then check if any other _OSC errors have been returned. Also
make it use the same error return value for all _OSC errors and print
a message for OSC_CAPABILITIES_MASK_ERROR like for the other error
types.

Moreover, make acpi_run_osc() only take the defined _OSC error bits into
account when checking _OSC errors.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/bus.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)

--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -194,6 +194,10 @@ static void acpi_print_osc_error(acpi_ha
pr_debug("\n");
}

+#define OSC_ERROR_MASK (OSC_REQUEST_ERROR | OSC_INVALID_UUID_ERROR | \
+ OSC_INVALID_REVISION_ERROR | \
+ OSC_CAPABILITIES_MASK_ERROR)
+
acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
{
acpi_status status;
@@ -240,8 +244,12 @@ acpi_status acpi_run_osc(acpi_handle han
status = AE_TYPE;
goto out_kfree;
}
- /* Need to ignore the bit0 in result code */
- errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
+ /* Only take defined error bits into account. */
+ errors = *((u32 *)out_obj->buffer.pointer) & OSC_ERROR_MASK;
+ /* If OSC_QUERY_ENABLE is set, ignore the "capabilities masked" bit. */
+ if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD] & OSC_QUERY_ENABLE)
+ errors &= ~OSC_CAPABILITIES_MASK_ERROR;
+
if (errors) {
if (errors & OSC_REQUEST_ERROR)
acpi_print_osc_error(handle, context,
@@ -252,17 +260,14 @@ acpi_status acpi_run_osc(acpi_handle han
if (errors & OSC_INVALID_REVISION_ERROR)
acpi_print_osc_error(handle, context,
"_OSC invalid revision");
- if (errors & OSC_CAPABILITIES_MASK_ERROR) {
- if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
- & OSC_QUERY_ENABLE)
- goto out_success;
- status = AE_SUPPORT;
- goto out_kfree;
- }
+ if (errors & OSC_CAPABILITIES_MASK_ERROR)
+ acpi_print_osc_error(handle, context,
+ "_OSC capability bits masked");
+
status = AE_ERROR;
goto out_kfree;
}
-out_success:
+
context->ret.length = out_obj->buffer.length;
context->ret.pointer = kmemdup(out_obj->buffer.pointer,
context->ret.length, GFP_KERNEL);