>-----Original Message----- >From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- >owner@xxxxxxxxxxxxxxx] On Behalf Of David Brownell >Sent: Tuesday, September 09, 2008 10:41 AM >To: Li, Shaohua >Cc: linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; >stern@xxxxxxxxxxxxxxxxxxx >Subject: Re: [RFC 0/5] device wakeup event support > >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 wake >> There are somethings we need discuss:up 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 >> >> 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. The ACPI mechanism works for all devices you mentioned here. It's not just for ACPI device. Thanks, Shaohua _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
