FAILED: patch "[PATCH] ACPI: sysfs: Change ACPI_MASKABLE_GPE_MAX to 0x100" failed to apply to 4.9-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From a7583e72a5f22470d3e6fd3b6ba912892242339f Mon Sep 17 00:00:00 2001
From: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>
Date: Thu, 14 Nov 2019 15:16:24 +0800
Subject: [PATCH] ACPI: sysfs: Change ACPI_MASKABLE_GPE_MAX to 0x100

The commit 0f27cff8597d ("ACPI: sysfs: Make ACPI GPE mask kernel
parameter cover all GPEs") says:
  "Use a bitmap of size 0xFF instead of a u64 for the GPE mask so 256
   GPEs can be masked"

But the masking of GPE 0xFF it not supported and the check condition
"gpe > ACPI_MASKABLE_GPE_MAX" is not valid because the type of gpe is
u8.

So modify the macro ACPI_MASKABLE_GPE_MAX to 0x100, and drop the "gpe >
ACPI_MASKABLE_GPE_MAX" check. In addition, update the docs "Format" for
acpi_mask_gpe parameter.

Fixes: 0f27cff8597d ("ACPI: sysfs: Make ACPI GPE mask kernel parameter cover all GPEs")
Signed-off-by: Yunfeng Ye <yeyunfeng@xxxxxxxxxx>
[ rjw: Use u16 as gpe data type in acpi_gpe_apply_masked_gpes() ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 8dee8f68fe15..02724bd017cc 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -113,7 +113,7 @@
 			the GPE dispatcher.
 			This facility can be used to prevent such uncontrolled
 			GPE floodings.
-			Format: <int>
+			Format: <byte>
 
 	acpi_no_auto_serialize	[HW,ACPI]
 			Disable auto-serialization of AML methods
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index 75948a3f1a20..c60d2c6d31d6 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -819,14 +819,14 @@ static ssize_t counter_set(struct kobject *kobj,
  * interface:
  *   echo unmask > /sys/firmware/acpi/interrupts/gpe00
  */
-#define ACPI_MASKABLE_GPE_MAX	0xFF
+#define ACPI_MASKABLE_GPE_MAX	0x100
 static DECLARE_BITMAP(acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) __initdata;
 
 static int __init acpi_gpe_set_masked_gpes(char *val)
 {
 	u8 gpe;
 
-	if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
+	if (kstrtou8(val, 0, &gpe))
 		return -EINVAL;
 	set_bit(gpe, acpi_masked_gpes_map);
 
@@ -838,7 +838,7 @@ void __init acpi_gpe_apply_masked_gpes(void)
 {
 	acpi_handle handle;
 	acpi_status status;
-	u8 gpe;
+	u16 gpe;
 
 	for_each_set_bit(gpe, acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) {
 		status = acpi_get_gpe_device(gpe, &handle);