Hi,
On Mon, Mar 03, 2025 at 01:52:52PM +0200, Abel Vesa wrote:
When determining the actual best period by looping through all possible PWM configs, the resolution currently used is based on bit shift value which is off-by-one above the possible maximum PWM value allowed.
So subtract one from the resolution before determining the best period so that the maximum duty cycle requested by the PWM user won't result in a value above the maximum allowed.
Cc: stable@vger.kernel.org # 6.4 Fixes: b00d2ed37617 ("leds: rgb: leds-qcom-lpg: Add support for high resolution PWM") Signed-off-by: Abel Vesa abel.vesa@linaro.org
Reviewed-by: Sebastian Reichel sre@kernel.org
Greetings,
-- Sebastian
drivers/leds/rgb/leds-qcom-lpg.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c index 0b6310184988c299d82ee7181982c03d306407a4..4f2a178e3d265a2cc88e651d3e2ca6ae3dfac2e2 100644 --- a/drivers/leds/rgb/leds-qcom-lpg.c +++ b/drivers/leds/rgb/leds-qcom-lpg.c @@ -462,7 +462,7 @@ static int lpg_calc_freq(struct lpg_channel *chan, uint64_t period) max_res = LPG_RESOLUTION_9BIT; }
- min_period = div64_u64((u64)NSEC_PER_SEC * (1 << pwm_resolution_arr[0]),
- min_period = div64_u64((u64)NSEC_PER_SEC * ((1 << pwm_resolution_arr[0]) - 1), clk_rate_arr[clk_len - 1]); if (period <= min_period) return -EINVAL;
@@ -483,7 +483,7 @@ static int lpg_calc_freq(struct lpg_channel *chan, uint64_t period) */ for (i = 0; i < pwm_resolution_count; i++) {
resolution = 1 << pwm_resolution_arr[i];
resolution = (1 << pwm_resolution_arr[i]) - 1;@@ -1292,7 +1292,7 @@ static int lpg_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, if (ret) return ret;
state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * (1 << resolution) *
state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * ((1 << resolution) - 1) * pre_div * (1 << m), refclk);-- 2.34.1