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[RFC] acpi/processor: Fix the return value of acpi_processor_ids_walk()

Message ID 20180717080921.24886-1-douly.fnst@cn.fujitsu.com (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Dou Liyang July 17, 2018, 8:09 a.m. UTC
ACPI driver should make sure all the processor IDs in their ACPI Namespace
are unique. the driver performs a depth-first walk of the namespace tree
and calls the acpi_processor_ids_walk() to check the duplicate IDs.

But, the acpi_processor_ids_walk() mistakes the return value. If a
processor is checked, it returns true which causes the walk break
immediately, and other processors will never be checked.

Repace the value with AE_OK which is the standard acpi_status value.
And don't abort the namespace walk even on error.

Fixes 8c8cb30f49b8 ("acpi/processor: Implement DEVICE operator for processor enumeration")
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
---
Changelog:
  The duplicate IDs may only be found in Ivb42 machine, and we added a check at linux-4.9.
  But, we introduced a bug in linux-4.12 by commit 8c8cb30f49b8.

  For resolving the bug, firstly, I want to remove the check[1]. because, Linux will check
  duplicate IDs when it hot-adds a physical CPU and only one of the processors with duplicate
  IDs will be used.

  But, I am not sure if All the processors with the some IDs will never be used ?
  With this patch, All the processors with the some IDs will never be hot-plugged.

  v1 --> v2:
   - Fix the check against duplicate IDs suggested by Rafael.

[1] https://lkml.org/lkml/2018/5/28/213
---
 drivers/acpi/acpi_processor.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox

Patch

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 449d86d39965..d90f669a395b 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -643,7 +643,7 @@  static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 
 	status = acpi_get_type(handle, &acpi_type);
 	if (ACPI_FAILURE(status))
-		return false;
+		return AE_OK;
 
 	switch (acpi_type) {
 	case ACPI_TYPE_PROCESSOR:
@@ -663,11 +663,12 @@  static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 	}
 
 	processor_validated_ids_update(uid);
-	return true;
+	return AE_OK;
 
 err:
+	/* Exit on error, but don't abort the namespace walk */
 	acpi_handle_info(handle, "Invalid processor object\n");
-	return false;
+	return AE_OK;
 
 }