[PATCH AUTOSEL 5.17 10/23] platform/x86: thinkpad_acpi: Correct dual fan probe

[Sasha Levin <sashal@kernel.org>]

From: Mark Pearson <markpearson@lenovo.com>

[ Upstream commit aa2fef6f40e6ccc22e932b36898f260f0e5a021a ]

There was an issue with the dual fan probe whereby the probe was
failing as it assuming that second_fan support was not available.

Corrected the logic so the probe works correctly. Cleaned up so
quirks only used if 2nd fan not detected.

Tested on X1 Carbon 10 (2 fans), X1 Carbon 9 (2 fans) and T490 (1 fan)

Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Link: https://lore.kernel.org/r/20220502191200.63470-1-markpearson@lenovo.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>
---
 drivers/platform/x86/thinkpad_acpi.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index c43586f1cb4b..0ea71416d292 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -8766,24 +8766,27 @@ static int __init fan_init(struct ibm_init_struct *iibm)
 			fan_status_access_mode = TPACPI_FAN_RD_TPEC;
 			if (quirks & TPACPI_FAN_Q1)
 				fan_quirk1_setup();
-			if (quirks & TPACPI_FAN_2FAN) {
-				tp_features.second_fan = 1;
-				pr_info("secondary fan support enabled\n");
-			}
-			if (quirks & TPACPI_FAN_2CTL) {
-				tp_features.second_fan = 1;
-				tp_features.second_fan_ctl = 1;
-				pr_info("secondary fan control enabled\n");
-			}
 			/* 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) {
 				/* It responded - so let's assume it's there */
 				tp_features.second_fan = 1;
 				tp_features.second_fan_ctl = 1;
 				pr_info("secondary fan control detected & enabled\n");
+			} else {
+				/* Fan not auto-detected */
+				tp_features.second_fan = 0;
+				if (quirks & TPACPI_FAN_2FAN) {
+					tp_features.second_fan = 1;
+					pr_info("secondary fan support enabled\n");
+				}
+				if (quirks & TPACPI_FAN_2CTL) {
+					tp_features.second_fan = 1;
+					tp_features.second_fan_ctl = 1;
+					pr_info("secondary fan control enabled\n");
+				}
 			}
-
 		} else {
 			pr_err("ThinkPad ACPI EC access misbehaving, fan status and control unavailable\n");
 			return -ENODEV;
-- 
2.35.1