[PATCH v2 13/33] HID: logitech-hidpp: fix K750 solar battery feature lookup and reconnect

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

In hidpp_solar_request_battery_event(), the driver checked whether
hidpp->battery.feature_index == 0xff instead of checking
solar_feature_index, causing it to re-query the root feature table
unnecessarily or misidentify whether the solar feature was resolved.

Furthermore, in hidpp_connect_event(), the HIDPP20_BATTERY block lacked
a branch for HIDPP_QUIRK_CLASS_K750, causing wireless reconnects of a
K750 keyboard to fall through to hidpp20_query_battery_info_1000() which
fails because the K750 does not implement feature 0x1000.

Check solar_feature_index in hidpp_solar_request_battery_event() and
re-enable solar battery reporting via the solar request helper on K750
reconnects.

Fixes: 696ecef9b587 ("HID: logitech-hidpp: add support for battery status for the K750")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hid-logitech-hidpp.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index f717f0308454..cdeb1b3c2f21 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -2122,7 +2122,7 @@ static int hidpp_solar_request_battery_event(struct hidpp_device *hidpp)
 	u8 params[2] = { 1, 1 };
 	int ret;
 
-	if (hidpp->battery.feature_index == 0xff) {
+	if (hidpp->battery.solar_feature_index == 0xff) {
 		ret = hidpp_root_get_feature(hidpp,
 					     HIDPP_PAGE_SOLAR_KEYBOARD,
 					     &hidpp->battery.solar_feature_index);
@@ -4582,7 +4582,9 @@ static void hidpp_connect_event(struct work_struct *work)
 		else
 			hidpp10_query_battery_status(hidpp);
 	} else if (hidpp->capabilities & HIDPP_CAPABILITY_HIDPP20_BATTERY) {
-		if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_VOLTAGE)
+		if (hidpp->quirks & HIDPP_QUIRK_CLASS_K750)
+			hidpp_solar_request_battery_event(hidpp);
+		else if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_VOLTAGE)
 			hidpp20_query_battery_voltage_info(hidpp);
 		else if (hidpp->capabilities & HIDPP_CAPABILITY_UNIFIED_BATTERY)
 			hidpp20_query_battery_info_1004(hidpp);

-- 
2.56.0.542.g3ef89b7020-goog