On Tue, 23 Feb 2010, Rafael J. Wysocki wrote: > > > I _think_ think the i915 KMS doesn't work on your box for some reason. > > > > > > Doesn the screen switch to the graphics framebuffer when booted with > > > vga=0? > > > > Yes, it does switch. > > OK > > > > If not, you probably need to enable framebuffer console in .config (the i915 > > > KMS depends on that actually). > > > > It's already enabled. That is, CONFIG_FB and > > CONFIG_FRAMEBUFFER_CONSOLE are both set to 'y'. > > Well, so the KMS suspend-resume doesn't work on your system. > > I guess that would require some detailed debugging, so it may be a good idea to > open a Bugzilla entry for this issue. Okay, I'll set it up later. > > > > Why are the values independent from the wakeup settings in sysfs? > > > > Aren't they supposed to mean the same thing? > > > > > > Not really. There are two separate flags for wakeup. One of them is a > > > property of the "physical" device object (eg. PCI device structure) and that > > > one is set/unset via sysfs. The other is a property of the device's ACPI > > > "shadow" object and is set/unset through /proc/acpi/wakeup (this mechanism > > > is regarded as obsolete, but it looks like some devices have not been converted > > > to the sysfs-based one yet). > > > > It looks like the inline routines defined in include/linux/pm_wakeup.h > > should call corresponding platform-specific routines. Apparently _no_ > > drivers have been converted in this way -- since the conversion needs > > to be part of the core. In fact, there isn't even a platform-specific > > hook for enabling or disabling wakeup devices; we should have a > > platform_wakeup_ops structure. > > There is one for PCI devices, actually. It's struct pci_platform_pm_ops() > defined in drivers/pci/pci.h. > > For PCI devices we have pci_enable_wake() that sets up the platform to > wake up the system using given device on the basis of the device's sysfs > setting. The ACPI flag shown by /proc/acpi/wakeup is not taken into account > in that case. That's not what I meant. Writing to /sys/devices/.../power/wakeup should have the same effect as writing to /proc/acpi/wakeup (if the device has a "shadow" ACPI counterpart, of course). It looks like /proc/acpi/wakeup does nothing but set acpidev->wakeup.state.enabled and warn about duplicate GPE usage. It would make sense to issue the warning when writing to the sysfs file. And wakeup.state.enabled shouldn't be needed at all; the ACPI code should always use the physical device's may_wakeup flag instead (unless there is no corresponding physical device). If writes to the sysfs file called a platform hook, we could warn about duplicate GPEs when the wakeup setting is changed. > Generally, you can think of two levels one can enable wakeup at. > First, there is the device level controlled by the sysfs wakeup setting. This > is how we would like to control wakeup. Second, however, there is the > /proc/acpi/wakeup interface allowing you to access the _internal_ ACPI > representation of devices directly and you can use that to set up the platform > to use the device for wakeup even if the device level mechanism doesn't work > or is not implemented for it (like in your case). > > IOW, the /proc/acpi/wakeup thing only tells us if the device is forced to do > the wakeup at the low level and it only takes the ACPI aspect of the wakeup > into account, which may not be sufficient. For exmaple, network adapters > (and other PCI devices) generally need to have the PME signaling enabled > in addition to the platform setup and the chip has to be enabled to take > wakeup packets from the network. > > If /proc/acpi/wakeup shows "enabled" this means "turn on the wakeup power > for this devices and enable its wakeup GPE unconditionally before suspend". > If it shows "disabled", it means "leave that to someone else" (that's analogous > to the "on" and "auto" settings for devices/.../power/control, but the names > are misleading for historical reasons). > > So, it looks like we need a counterpart of pci_enable_wake() for PNP devices. That sounds reasonable. ACPI could be made to work without such a thing, but other platforms probably would need it. Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
