Re: [PATCH] hp-wmi: limit hotkey enable

[Kyle Evans <kvans32@gmail.com>]

 From 7d11e942d2c84919ded37b46a72be59f34141c5d Mon Sep 17 00:00:00 2001
From: Kyle Evans <kvans32@gmail.com>
Date: Tue, 1 Sep 2015 18:50:45 -0500
Subject: [PATCH] hp-wmi: limit hotkey enable

Do not write initialize magic on systems that do not have
feature query 0xb. Fixes Bug #82451.

Define a new feature query to differentiate older systems and rename
FEATURE_QUERY, 0xd, to FEATURE2_QUERY for code consistency.
Also, some return value magic number cleanup.
---
  drivers/platform/x86/hp-wmi.c | 28 +++++++++++++++++++---------
  1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
index 0669731..c0a7817 100644
--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -54,8 +54,9 @@ MODULE_ALIAS("wmi:5FB7F034-2C63-45e9-BE91-3D44E2C707E4");
  #define HPWMI_HARDWARE_QUERY 0x4
  #define HPWMI_WIRELESS_QUERY 0x5
  #define HPWMI_BIOS_QUERY 0x9
+#define HPWMI_FEATURE_QUERY 0xb
  #define HPWMI_HOTKEY_QUERY 0xc
-#define HPWMI_FEATURE_QUERY 0xd
+#define HPWMI_FEATURE2_QUERY 0xd
  #define HPWMI_WIRELESS2_QUERY 0x1b
  #define HPWMI_POSTCODEERROR_QUERY 0x2a

@@ -295,7 +296,7 @@ static int hp_wmi_tablet_state(void)
  	return (state & 0x4) ? 1 : 0;
  }

-static int __init hp_wmi_bios_2009_later(void)
+static int __init hp_wmi_bios_2008_later(void)
  {
  	int state = 0;
  	int ret = hp_wmi_perform_query(HPWMI_FEATURE_QUERY, 0, &state,
@@ -306,14 +307,22 @@ static int __init hp_wmi_bios_2009_later(void)
  	return (state & 0x10) ? 1 : 0;
  }

-static int hp_wmi_enable_hotkeys(void)
+static int __init hp_wmi_bios_2009_later(void)
  {
-	int ret;
-	int query = 0x6e;
+	int state = 0;
+	int ret = hp_wmi_perform_query(HPWMI_FEATURE2_QUERY, 0, &state,
+				       sizeof(state), sizeof(state));
+	if (ret)
+		return ret;

-	ret = hp_wmi_perform_query(HPWMI_BIOS_QUERY, 1, &query, sizeof(query),
-				   0);
+	return (state & 0x10) ? 1 : 0;
+}

+static int hp_wmi_enable_hotkeys(void)
+{
+	int value = 0x6e;
+	int ret = hp_wmi_perform_query(HPWMI_BIOS_QUERY, 1, &value,
+				       sizeof(value), 0);
  	if (ret)
  		return -EINVAL;
  	return 0;
@@ -663,8 +672,9 @@ static int __init hp_wmi_input_setup(void)
  			    hp_wmi_tablet_state());
  	input_sync(hp_wmi_input_dev);

-	if (hp_wmi_bios_2009_later() == 4)
-		hp_wmi_enable_hotkeys();
+	if (hp_wmi_bios_2009_later() == HPWMI_RET_UNKNOWN_CMDTYPE)
+		if !(hp_wmi_2008_later() == HPWMI_RET_UNKNOWN_CMDTYPE)
+			hp_wmi_enable_hotkeys();

  	status = wmi_install_notify_handler(HPWMI_EVENT_GUID, hp_wmi_notify, 
NULL);
  	if (ACPI_FAILURE(status)) {
-- 
1.8.5.5


If this is ok I'll add my sign-off and resend. I agree that the return 
state of hp_wmi_enable_hotkeys is lacking, but the only thing that I see 
error handling realistically doing in this case is adding code cruft and 
processing cycles. If you would like anything further, let me know.