Hi, On 09/17/2017 08:22 PM, Pavel Machek wrote: > Hi! > >>> If your objection is that FF is not easily engaged from the shell - >>> yes, but I do not think that actual users who want to do vibration do >>> that via shell either. On the other hand, can you drop privileges and >>> still allow a certain process control your vibrator via LED interface? >>> With FF you can pass an FD to whoever you deem worthy and later revoke >>> access. >>> >>> IOW sysfs interfaces are nice for quick hacks, but when you want to >>> use them in real frameworks, where you need to think about proper >>> namespaces, isolation, etc, etc, other kinds of interfaces might suit >>> better. >> >> I'd leave the decision to the user. We could add a note to the >> Documentation/leds/ledtrig-transient.txt that force feedback interface >> should be preferable choice for driving vibrate devices. > > We don't want to leave decision to the user; because then we'll end up > with userland applications having to support _both_ interfaces. This state has lasted for five years now. I don't recall any complaints. Do you? > Plus, it is not really your decision. Dmitry is maintainer of input > subsystem, input was doing force feedback for 10+ years, and he > already made a decision. It seems that you applied a fait accompli method here. Actually could you share what the decision is? AFAIK we're not discussing here any patch for the input subsystem? >> However only if following conditions are met: >> - force feedback driver supports gpio driven devices >> - there is sample application in tools/input showing how to >> setup gpio driven vibrate device with use of ff interface >> - it will be possible to setup vibrate interval with 1ms accuracy, >> similarly to what the discussed patch allows to do > > I agree these would be nice. Interested parties are welcome to help > there. But I don't think this should have any impact on LED > susbystem. Force feedback just does not belong to LED subsystem. You cut off important piece of my text from the beginning of this paragraph. It was: > I'd leave the decision to the user. We could add a note to the > Documentation/leds/ledtrig-transient.txt that force feedback interface > should be preferable choice for driving vibrate devices. > However only if following conditions are met: What I meant is that it is my decision, as a LED subsystem maintainer, to accept the addition of a note about some other subsystem offering an equivalent or even better substitute of the feature being available in the subsystem I am responsible for. And I will accept such a patch only if mentioned conditions are met. -- 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
