[PATCH] platform/x86: thinkpad_acpi: skip invalid fan speed

[Jelle van der Waa <jvanderwaa@redhat.com>]

65535 is most likely an invalid read.

Signed-off-by: Jelle van der Waa <jvanderwaa@redhat.com>

---

Cc: Mark Pearson <markpearson@lenovo.com>
---
 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 6a823b850a77..20e5c043a8e8 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -263,6 +263,8 @@ enum tpacpi_hkey_event_t {
 #define TPACPI_DBG_BRGHT	0x0020
 #define TPACPI_DBG_MIXER	0x0040
 
+#define FAN_NOT_PRESENT		65535
+
 #define strlencmp(a, b) (strncmp((a), (b), strlen(b)))
 
 
@@ -8876,7 +8878,7 @@ static int __init fan_init(struct ibm_init_struct *iibm)
 			/* Try and probe the 2nd fan */
 			tp_features.second_fan = 1; /* needed for get_speed to work */
 			res = fan2_get_speed(&speed);
-			if (res >= 0) {
+			if (res >= 0 && speed != FAN_NOT_PRESENT) {
 				/* It responded - so let's assume it's there */
 				tp_features.second_fan = 1;
 				tp_features.second_fan_ctl = 1;
-- 
2.38.1