[PATCH input-wacom 02/10] backport: HID: wacom: leds: Don't try to control the EKR's read-only LEDs

[Jason Gerecke <killertofu@gmail.com>]

From: Aaron Armstrong Skomra <skomra@gmail.com>

Commit a50aac7193f1 introduces 'led.groups' and adds EKR support
for these groups. However, unlike the other devices with LEDs,
the EKR's LEDs are read-only and we shouldn't attempt to control
them in wacom_led_control().

See bug: https://sourceforge.net/p/linuxwacom/bugs/342/

Fixes: a50aac7193f1 ("backport: HID: wacom: leds: dynamically allocate LED groups")
Cc: stable <stable@vger.kernel.org>     # 4.9
Signed-off-by: Aaron Armstrong Skomra <aaron.skomra@wacom.com>
Reviewed-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
[jason.gerecke@wacom.com: Imported into input-wacom repository (74aebed6dc)]
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
[jason.gerecke@wacom.com: Backported from input-wacom repository (7a69536)]
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
---
 3.17/wacom_sys.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/3.17/wacom_sys.c b/3.17/wacom_sys.c
index 2996d0d..8fd0b78 100644
--- a/3.17/wacom_sys.c
+++ b/3.17/wacom_sys.c
@@ -794,6 +794,9 @@ static int wacom_led_control(struct wacom *wacom)
 	if (!wacom->led.groups)
 		return -ENOTSUPP;
 
+	if (wacom->wacom_wac.features.type == REMOTE)
+		return -ENOTSUPP;
+
 	if (wacom->wacom_wac.pid) { /* wireless connected */
 		report_id = WAC_CMD_WL_LED_CONTROL;
 		buf_size = 13;
-- 
2.14.1