On Friday, 19 of September 2008, Zhang, Rui wrote: > >From: Len Brown [mailto:lenb@xxxxxxxxxxxxxxx] > >Sent: Friday, September 19, 2008 12:33 AM > >To: dmitry.torokhov@xxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; rjw@xxxxxxx; Zhang, > >Rui > >Subject: Re: /proc/acpi/ removal plan > > > >> processor throttling state I/F > >> As processor T-state is used for thermal control only, > >> processor t-state is mapped to a cooling_device's cooling_state > >> in the generic thermal driver, combined with the processor's p-state. > > > >> # ls -l /sys/class/thermal/cooling_device0/ > > > >When I scribble into cur_state > >I do not see anything reflected in > >/proc/acpi/processor/*/throttling > > > >Also, max_state is 10, when surely my processor > >has only 8 T-states. > > > the cooling state of processor is a combination of p-state and t-state. > because reducing the frequency is preferred when system is overheat. > e.g cooling state 0 mean processor can be run in the maximum frequency, and it's in the T0 state. And cooling state 9 means processor is in the minimum frequency, T7 state. > > >If user-space can not provoke processor T-states via this I/F, > >then those using the old /proc I/F will flag it as a regression > >when it goes away. (even if few should ever need it) > > > >> wakeup control, > >> /sys/devices/.../wakeup should be in the todo list. :) > > > >I thought that Rafael said the wakeup file > >in the device tree was working now -- at least > >for PCI devices, no? > > > Rafael's patch did bind the "wakeup" file together with the ACPI device. > It calls the acpi_enable_wakeup_device_power of the ACPI device, but it > doesn't touch the wakeup GPE at all. So, I don't think it actually works... Have you noticed that the GPEs are actually set up right before entering the sleep state? acpi_enable_wakeup_device() does that, so in fact yes, it does work. > > >I think the biggest problem with sysfs wakeup is that every > >device in the tree gets a wakeup file, even if it > >has no wakeup capability... > > > that's okay. > The wakeup file return null string if it doesn't have the wakeup ability. > To be honest, there is one thing that I'm still concerned about. > The wakeup file is a runtime device wakeup flag rather than a system wakeup > flag. i.e. "enabled" means that the device can be suspend/resumed at > runtime. No, it is _NOT_. 'enabled' means that the device is allowed to wake up the system from a sleep state if so configured. > It doesn't ensure that it can wakeup the system from a sleep state. > If /proc/acpi/wakeup is replaced by the /sys/devices/.../wakeup, users may > be confused because the device can not wakeup the system even if the wakeup > file is set to "enabled". That is actually true, but OTOH there's no any 'binary' interface that can be used for that, because for example network adapters can wake-up the system in many different situations (ie. they can react to many different types of packets). To avoid the confusion, I started to change the wake-on-LAN ioctls of network adapters so that they update the 'wakeup' flag whey the device is set up to wake up. > >> button sys I/F can be found at /sys/class/input/. > >> e.g. > >> # cat /sys/class/input/input*/device/hid > >> LNXPWRBN > >> PNP0C0C > > > >The /proc files for power and sleep buttons simply > >told us what kind of button they were, just info, not API. > > > >The functional one is PNP0C0D, the lid switch. > >It is also reflected in /sys/class/input, but I don't > >see a way to find from /sys the open/closed state > >like we have in /proc. (I ran into this when I tried > >to delete the button /proc I/F some time ago). > > > You're right. Lid device still needs such an I/F. This is correct, /proc/wakeup is necessary for devices like that. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
