From 720ef73d1a239e33c3ad8fac356b9b1348e68aaf Mon Sep 17 00:00:00 2001
From: Aaron Ma <aaron.ma@canonical.com>
Date: Sat, 3 Oct 2020 01:09:16 +0800
Subject: [PATCH] platform/x86: thinkpad_acpi: re-initialize ACPI buffer size when reuse
Git-commit: 720ef73d1a239e33c3ad8fac356b9b1348e68aaf
Patch-mainline: v5.9
References: git-fixes
Evaluating ACPI _BCL could fail, then ACPI buffer size will be set to 0.
When reuse this ACPI buffer, AE_BUFFER_OVERFLOW will be triggered.
Re-initialize buffer size will make ACPI evaluate successfully.
Fixes: 46445b6b896fd ("thinkpad-acpi: fix handle locate for video and query of _BCL")
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/platform/x86/thinkpad_acpi.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 7cb3b71c67fe..e5a62fa9a879 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6829,8 +6829,10 @@ static int __init tpacpi_query_bcl_levels(acpi_handle handle)
list_for_each_entry(child, &device->children, node) {
acpi_status status = acpi_evaluate_object(child->handle, "_BCL",
NULL, &buffer);
- if (ACPI_FAILURE(status))
+ if (ACPI_FAILURE(status)) {
+ buffer.length = ACPI_ALLOCATE_BUFFER;
continue;
+ }
obj = (union acpi_object *)buffer.pointer;
if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
--
2.16.4