From 720ef73d1a239e33c3ad8fac356b9b1348e68aaf Mon Sep 17 00:00:00 2001 From: Aaron Ma Date: Sat, 3 Oct 2020 01:09:16 +0800 Subject: [PATCH] platform/x86: thinkpad_acpi: re-initialize ACPI buffer size when reuse 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 Signed-off-by: Andy Shevchenko --- 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 7cb3b71..e5a62fa 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)) { -- 2.7.4