On 05/08/2017 11:06 PM, Pavel Machek wrote: > On Sun 2017-04-30 14:36:58, David Lin wrote: >> Hi, >> >> These patch series add the LED_BRIGHTNESS_FAST flag support for >> ledtrig-transient to use hrtimer so that platforms with high-resolution timer >> support can have better accuracy in the trigger duration timing. The need for >> this support is driven by the fact that Android has removed the timed_ouput [1] >> and is now using led-trigger for handling vibrator control which requires the >> timer to be accurate up to a millisecond. However, this flag support would also >> allow hrtimer to co-exist with the ktimer without causing warning to the >> existing drivers [2]. > > Yes, and objection still stands: You are misusing LED subsystem for > vibration motors. We already have support for haptic feedback in input > subsystem. Regardless of whether it is a misuse or not (ledtrig-transient documentation suggests that it is one of use cases) we have to keep it as it has been around for a long time and it has userspace users [0]. Moreover there seems to be broad consensus about it among kernel people [1]. [0] https://android.googlesource.com/platform%2Fhardware%2Flibhardware/+/61701df363310a5cbd95e3e1638baa9526e42c9b [1] https://patchwork.kernel.org/patch/8664831/ -- Best regards, Jacek Anaszewski -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
