platform/x86: thinkpad_acpi: Fix reporting a non present second fan on some models

[ Upstream commit a10d50983f ]

thinkpad_acpi was reporting 2 fans on a ThinkPad T14s gen 1, even though
the laptop has only 1 fan.

The second, not present fan always reads 65535 (-1 in 16 bit signed),
ignore fans which report 65535 to avoid reporting the non present fan.

Signed-off-by: Jelle van der Waa <jvanderwaa@redhat.com>
Link: https://lore.kernel.org/r/20221019194751.5392-1-jvanderwaa@redhat.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jelle van der Waa 2022-10-19 21:47:51 +02:00 committed by Greg Kroah-Hartman
parent 1ee83fc520
commit f8d00ab09c

View file

@ -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;