[PATCH 2/2] platform/x86: acer-wmi: Fix missing capability check

[Armin Wolf <W_Armin@gmx.de>]

During the rework of the fan behavior control code in commit
d8e8362b09d3 ("platform/x86: acer-wmi: Fix setting of fan behavior"),
acer_toggle_turbo() was changed to use WMID_gaming_set_fan_behavior()
instead of WMID_gaming_set_u64() when switching the fans to turbo
mode. The new function however does not check if the necessary
capability (ACER_CAP_TURBO_FAN) is actually enabled on a given
machine, causing the driver to potentially access unsupported
features.

Fix this by manually checking if ACER_CAP_TURBO_FAN is enabled
on a given machine before changing the fan mode.

Cc: stable@vger.kernel.org
Fixes: d8e8362b09d3 ("platform/x86: acer-wmi: Fix setting of fan behavior")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/platform/x86/acer-wmi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 54ca3edf532a..e0eaaefb13d0 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -2070,7 +2070,8 @@ static int acer_toggle_turbo(void)
 		WMID_gaming_set_u64(0x1, ACER_CAP_TURBO_LED);
 
 		/* Set FAN mode to auto */
-		WMID_gaming_set_fan_mode(ACER_WMID_FAN_MODE_AUTO);
+		if (has_cap(ACER_CAP_TURBO_FAN))
+			WMID_gaming_set_fan_mode(ACER_WMID_FAN_MODE_AUTO);
 
 		/* Set OC to normal */
 		if (has_cap(ACER_CAP_TURBO_OC)) {
@@ -2084,7 +2085,8 @@ static int acer_toggle_turbo(void)
 		WMID_gaming_set_u64(0x10001, ACER_CAP_TURBO_LED);
 
 		/* Set FAN mode to turbo */
-		WMID_gaming_set_fan_mode(ACER_WMID_FAN_MODE_TURBO);
+		if (has_cap(ACER_CAP_TURBO_FAN))
+			WMID_gaming_set_fan_mode(ACER_WMID_FAN_MODE_TURBO);
 
 		/* Set OC to turbo mode */
 		if (has_cap(ACER_CAP_TURBO_OC)) {
-- 
2.52.0