Hi Jacek, On 5 December 2017 at 20:38, Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> wrote: > Hi Ben, > > On 12/05/2017 12:19 PM, Ben Whitten wrote: >> From: Ben Whitten <ben.whitten@xxxxxxxxx> >> >> The patch was converted to led_blink_oneshot, in doing so we find that the >> behaviour has changed. As I dont want to break 'userspace' led behaviour this >> patch shouldn't be merged as is. Open to suggestions. >> >> Given an interval of 50ms and heavy throughput, the previous implementation >> produced a blink with 100ms period and 50% dutycycle. The led_blink_oneshot >> version produces a blink with 140ms period and 57% dutycycle. > > Please check if the LED class driver you're testing the trigger with > implements blink_set op. If yes it would be good to check if it doesn't > align the delay intervals to the hardware capabilities instead of > failing and relying on a LED core software blink fallback. The led are using gpio-led set from device tree on an embedded system, sama5 based. So as far as I can tell blink_op is NULL in this case and it then relies on software for the blink in the form of timers. I assume its the jiffies playing a part here, taking a jiffy or two to queue up a flash may add 10ms to the desired 50ms delay_on/delay_off that I am seeing. Then the extra time may be due to the stats workqueue not aligning with the blink timer to kick it off again. Best regards, Ben
