platform/x86: hp-wmi: Do not shadow error values

BugLink: http://bugs.launchpad.net/bugs/1732698

commit d3138769 upstream.

All the helper functions (i.e. hp_wmi_dock_state, hp_wmi_tablet_state,
...) using hp_wmi_perform_query to perform an HP WMI query shadow the
returned value in case of error.

We return -EINVAL only when the HP WMI query returns a positive value
(the specific error code) to not mix this up with the actual value
returned by the helper function.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Cc: Philip Müller <philm@manjaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

drivers/platform/x86/hp-wmi.c

@@ -249,7 +249,7 @@ static int hp_wmi_display_state(void)
 	int ret = hp_wmi_perform_query(HPWMI_DISPLAY_QUERY, 0, &state,
 				       sizeof(state), sizeof(state));
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 	return state;
 }
 
@@ -259,7 +259,7 @@ static int hp_wmi_hddtemp_state(void)
 	int ret = hp_wmi_perform_query(HPWMI_HDDTEMP_QUERY, 0, &state,
 				       sizeof(state), sizeof(state));
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 	return state;
 }
 
@@ -269,7 +269,7 @@ static int hp_wmi_als_state(void)
 	int ret = hp_wmi_perform_query(HPWMI_ALS_QUERY, 0, &state,
 				       sizeof(state), sizeof(state));
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 	return state;
 }
 
@@ -280,7 +280,7 @@ static int hp_wmi_dock_state(void)
 				       sizeof(state), sizeof(state));
 
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 
 	return state & 0x1;
 }
@@ -291,7 +291,7 @@ static int hp_wmi_tablet_state(void)
 	int ret = hp_wmi_perform_query(HPWMI_HARDWARE_QUERY, 0, &state,
 				       sizeof(state), sizeof(state));
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 
 	return (state & 0x4) ? 1 : 0;
 }
@@ -324,7 +324,7 @@ static int __init hp_wmi_enable_hotkeys(void)
 	int ret = hp_wmi_perform_query(HPWMI_BIOS_QUERY, 1, &value,
 				       sizeof(value), 0);
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 	return 0;
 }
 
@@ -337,7 +337,7 @@ static int hp_wmi_set_block(void *data, bool blocked)
 	ret = hp_wmi_perform_query(HPWMI_WIRELESS_QUERY, 1,
 				   &query, sizeof(query), 0);
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 	return 0;
 }
 
@@ -429,7 +429,7 @@ static int hp_wmi_post_code_state(void)
 	int ret = hp_wmi_perform_query(HPWMI_POSTCODEERROR_QUERY, 0, &state,
 				       sizeof(state), sizeof(state));
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 	return state;
 }
 
@@ -495,7 +495,7 @@ static ssize_t set_als(struct device *dev, struct device_attribute *attr,
 	int ret = hp_wmi_perform_query(HPWMI_ALS_QUERY, 1, &tmp,
 				       sizeof(tmp), sizeof(tmp));
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 
 	return count;
 }
@@ -516,7 +516,7 @@ static ssize_t set_postcode(struct device *dev, struct device_attribute *attr,
 	ret = hp_wmi_perform_query(HPWMI_POSTCODEERROR_QUERY, 1, &tmp,
 				       sizeof(tmp), sizeof(tmp));
 	if (ret)
-		return -EINVAL;
+		return ret < 0 ? ret : -EINVAL;
 
 	return count;
 }