[PATCH v2] thinkpad_acpi: return -NODEV while operating uninitialized LEDs

[Adam Lee]

Not all 0-15 LEDs are available for all models, sometimes it's even not
safe. This patch return -NODEV while operating uninitialized LEDs.

Signed-off-by: Adam Lee <adam.lee@xxxxxxxxxxxxx>
---
 drivers/platform/x86/thinkpad_acpi.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 54d31c0..d2ac4e8 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -5401,9 +5401,12 @@ static int led_write(char *buf)
 		return -ENODEV;
 
 	while ((cmd = next_cmd(&buf))) {
-		if (sscanf(cmd, "%d", &led) != 1 || led < 0 || led > 15)
+		if (sscanf(cmd, "%d", &led) != 1 || led < 0 || led > (TPACPI_LED_NUMLEDS -1))
 			return -EINVAL;
 
+		if (!tpacpi_leds[led].led)
+			return -ENODEV;
+
 		if (strstr(cmd, "off")) {
 			s = TPACPI_LED_OFF;
 		} else if (strstr(cmd, "on")) {
-- 
1.7.10.4

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