On Monday 08 September 2008, shaohua.li@xxxxxxxxx wrote: > This series add device wakeup event detection support. This is the base to > implement runtime device suspend/resume, though we don't support it now. > But David said USB is approaching to this. See this bugzilla > http://bugzilla.kernel.org/show_bug.cgi?id=6892 for detail. Glad to see more attention here. :) Note that this issue is specific to systems using PCI (at core), with additional nuances for PCI systems which use ACPI. Device wakeup through USB works fine on various non-PCI and non-ACPI embedded systems, without needing these patches. It's done so for several years now... > The current process to handle wakeup event is: > 1. driver enable wakeup event line pme and suspend > 2. NPME or ACPI receives wakeup event > 3. NPME or ACPI call .wakeup_event() to clear and disable wakeup > event. Driver can do extra things in .wakeup_event() too. > 4. NPME or ACPI call generic wakeup event handler (device_receive_wakeup_event()) > 5. device resumes, and goto 1 for next round of suspend > > There are somethings we need discuss: > 1. is this generic for other platforms? > 2. what should the generic wakeup event handler do? > > Comments and suggestions are welcome! My reaction re "generic" is that these mechanisms should be specific to the busses and platforms involved; see my comments on patch #1. However this means that for PCI devices, or PCIE, this can and should be generic enough to work on non-x86 systems. It's not quite that generic yet, and there are interactions between PCI/PCIE and ACPI that will need work. But having those layers clean is important; and you've got a decent start on that. Plus there are various other wake-capable devices, like the PS2 devices and UART in /proc/acpi/wakeup on one of my systems: Device S-state Status Sysfs node PCI0 S4 disabled no-bus:pci0000:00 PS2M S4 disabled pnp:00:05 PS2K S4 disabled pnp:00:06 UAR1 S4 disabled pnp:00:08 USB1 S3 disabled pci:0000:00:03.0 USB2 S3 disabled pci:0000:00:03.1 USB3 S3 disabled <-- BIOS bug: no such hardware USB4 S3 disabled pci:0000:00:03.3 S139 S4 disabled <-- BIOS bug: no such hardware LAN S4 disabled pci:0000:00:04.0 MDM S4 disabled <-- MDM and AUD are the same HW?? AUD S4 disabled pci:0000:00:02.7 SLPB S4 *enabled But getting a good start on the PCI and ACPI runtime wake framework will help a lot. - Dave -- 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
