Ulf Hansson <ulf.hansson@xxxxxxxxxx> writes: > I think it is kind of strange to give provision to userspace to > control a "request based" power management feature in the kernel. Me > personally can't think of any good use case, but I comes from the > embedded/ARM world so I might not have the full picture. Because resuming a device inevitably adds latency, and that only userspace can decide the latency vs power policy for any given device, system and user? There are also other reasons, mostly related to device bugs. But the above is the most important in my view. Without that control knob I don't think I would have enabled runtime PM in any network driver while the netif is running. The additional latency is noticable. Anyway, this is a pointless discussion. The power/control ABI is in use so many places that it cannot be changed. I'd suggest googling "break userspace" before even suggesting anything like that again. Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
