![]() | ||||||||||
Messages in this thread |
Henrique de Moraes Holschuh wrote: > On Fri, 08 Feb 2008, Németh Márton wrote: >> Richard Purdie wrote: >>>>> leds: Add support for hardware accelerated LED flashing >>>> This one has a loose end: when you call brightness_set on a led with >>>> hardware flash acceleration, you will leave the trigger armed, BUT the led >>>> won't blink anymore. That's just wrong. >>> Agreed. >> My only question is that do you know any LED hardware which can blink _and_ >> can set the brightness independently? If there would be such a LED I could > > Several, but none on laptops or other stuff that runs Linux. That behaviour > is not common on indicator LEDs. I have seen standby LEDs on laptops which > "blink" by slowly fading from full to off, and then back to full, though. > >> imagine that the brightness can be changed while the LED remains blinking at >> some low frequency. For example a simple LED with brightness set possibility and >> blinking directed by software is an example where the blinking and the brightness >> setting are completely independent. > > Sure, it is perfectly possible. I am not sure it is *desireable*, though. > The way we have triggers work make what you describe impossible right now, > the software triggers are LED_OFF:LED_FULL, not LED_OFF:old-brightness. > > And so are the common hardware triggers on laptops, for that matter. > > If we go and fix every trigger to use the current brightness (as long as it > is non-zero) as the "turn LED on" trigger event, then the documentation has > to be changed accordingly to do what you said above, and we would stop the > trigger only by setting brightness to zero or by explicitly removing it. > > I don't think it is worth the hassle, though. But we better decide that > *now*, because all this changing of the LED class ABI (even if it is, IMHO, > a big improvement) is not a good idea. We better do it all during the > 2.6.25 cycle. I investigated what would have to be changed if we decide that the brightness and the blinking parameters can be set independently. There are not much too change I think, please have a look at my next mail. Márton Németh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | |||||||||
| Last update: 2008-02-10 12:55 [from the cache] ©2003-2008 | ||||||||||