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These differ when supported token bits are not consecutive starting at bit 0. Count the supported token bits below the active token with hweight16() to recover its zero-based brightness ordinal. Return zero directly when ret == 0: token bit 0 has no supported tokens below it, so its brightness ordinal is zero. Signed-off-by: Yury Norov --- drivers/platform/x86/dell/dell-laptop.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/platform/x86/dell/dell-laptop.c b/drivers/platform/x86/dell/dell-laptop.c index 03d3bb70b0d1..55fd48222e5e 100644 --- a/drivers/platform/x86/dell/dell-laptop.c +++ b/drivers/platform/x86/dell/dell-laptop.c @@ -2003,7 +2003,6 @@ static const struct attribute_group *kbd_led_groups[] = { static enum led_brightness kbd_led_level_get(struct led_classdev *led_cdev) { int ret; - u16 num; struct kbd_state state; if (kbd_get_max_level()) { @@ -2018,13 +2017,10 @@ static enum led_brightness kbd_led_level_get(struct led_classdev *led_cdev) if (kbd_get_valid_token_counts()) { ret = kbd_get_first_active_token_bit(); - if (ret < 0) - return 0; - for (num = kbd_token_bits; num != 0 && ret > 0; --ret) - num &= num - 1; /* clear the first bit set */ - if (num == 0) + if (ret <= 0) return 0; - return ffs(num) - 1; + /* Brightness is the active token's rank among supported tokens. */ + return hweight16(kbd_token_bits & GENMASK(ret - 1, 0)); } pr_warn("Keyboard brightness level control not supported\n"); -- 2.53.0