Re: [PATCH] ACPI: Add sysfs interface for acpi device wakeup

[Zhang Rui <rui.zhang@intel.com>]

On Thu, 2008-01-10 at 09:43 +0200, Maxim Levitsky wrote:
> On Thursday, 10 January 2008 00:21:46 Yi Yang wrote:
> > Subject: ACPI: convert procfs to sysfs for /proc/acpi/wakeup
> > From: Yi Yang <yi.y.yang@intel.com>
> > 
> > /proc/acpi/wakeup is deprecated but it has to exist because
> > we haven't a sysfs interface to replace it yet, this patch
> > converts /proc/acpi/wakeup to sysfs interface, under every
> > acpi device sysfs node, a user can see a directory "wakeup"
> > if the acpi device can support wakeup, there are six files
> > under this directory:
> > 
> > acpi_bus_id  bus_id  pci_id  run_wakeup  sleep_state  status
> > 
> > All the files are read-only exclude "status" which is used
> > to enable or disable wakeup of the acpi device.
> > 
> > "acpi_bus_id" is acpi bus ID of the acpi device.
> > 
> > "bus_id" is pci bus id of the device associated to the acpi
> > device, it will be empty if there isn't any device associated
> > to it.
> > 
> > "pci_id" is PCI ID of the pci device associated to the acpi
> > device, it will be empty if there isn't any device associated
> > to it.
> > 
> > "run_wake" is a flag indicating if a wakeup process is being
> > handled.
> > 
> > "sleep_state" is sleep state of the acpi device such as "S0".
> > 
> > "status" is wakeup status of the acpi device, it is enabled
> > or disabled, a user can change it be echoing "0", "1",
> > "disabled" or "enabled" to /sys/devices/.../wakeup/status. 
> > 
> > Here is the test result:
> > 
> > [root@localhost ~]# cat /proc/acpi/wakeup
> > Device  S-state   Status   Sysfs node           PCI ID
> > C093      S5     disabled  pci:0000:00:1e.0     0x2448
> > C0E8      S3     disabled  pci:0000:00:1d.0     0x27c8
> > C0EF      S3     disabled  pci:0000:00:1d.1     0x27c9
> > C0F0      S3     disabled  pci:0000:00:1d.2     0x27ca
> > C0F1      S3     disabled  pci:0000:00:1d.3     0x27cb
> > C0F2      S3     disabled  pci:0000:00:1d.7     0x27cc
> > C0F9      S0     disabled  pci:0000:00:1c.0     0x27d0
> > C21D      S0     disabled  pci:0000:08:00.0     0x16fd
> > C109      S5     disabled  pci:0000:00:1c.1     0x27d2
> > C228      S5     disabled  pci:0000:10:00.0     0x4222
> > C10F      S5     disabled  pci:0000:00:1c.3     0x27d6
> > C229      S5     disabled
> > [root@localhost ~]# find /sys -name "*" | grep sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:05/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:0d/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:11/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:15/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:19/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:1d/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2b/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2b/device:2c/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2d/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2d/device:2e/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/wakeup/sleep_state
> > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/sleep_state
> > [root@localhost ~]# ls /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup
> > acpi_bus_id  bus_id  pci_id  run_wakeup  sleep_state  status
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/acpi_bus_id
> > cat: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/acpi_bus_id: No such file or directory
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/acpi_bus_id
> > C229
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/sleep_state
> > S5
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/status
> > disabled
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/bus_id
> > 
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/pci_id
> > 
> > [root@localhost ~]# echo 1 > /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/status
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:2f/device:30/wakeup/status
> > enabled
> > [root@localhost ~]# cat /proc/acpi/wakeup
> > Device  S-state   Status   Sysfs node           PCI ID
> > C093      S5     disabled  pci:0000:00:1e.0     0x2448
> > C0E8      S3     disabled  pci:0000:00:1d.0     0x27c8
> > C0EF      S3     disabled  pci:0000:00:1d.1     0x27c9
> > C0F0      S3     disabled  pci:0000:00:1d.2     0x27ca
> > C0F1      S3     disabled  pci:0000:00:1d.3     0x27cb
> > C0F2      S3     disabled  pci:0000:00:1d.7     0x27cc
> > C0F9      S0     enabled   pci:0000:00:1c.0     0x27d0
> > C21D      S0     enabled   pci:0000:08:00.0     0x16fd
> > C109      S5     enabled   pci:0000:00:1c.1     0x27d2
> > C228      S5     enabled   pci:0000:10:00.0     0x4222
> > C10F      S5     enabled   pci:0000:00:1c.3     0x27d6
> > C229      S5     enabled
> > [root@localhost ~]# vi /var/log/dmesg
> > [root@localhost ~]# dmesg | grep "same GPE"
> > ACPI: 'C0F9' and 'C229' have the same GPE, can't disable/enable one seperately
> > ACPI: 'C21D' and 'C229' have the same GPE, can't disable/enable one seperately
> > ACPI: 'C109' and 'C229' have the same GPE, can't disable/enable one seperately
> > ACPI: 'C228' and 'C229' have the same GPE, can't disable/enable one seperately
> > ACPI: 'C10F' and 'C229' have the same GPE, can't disable/enable one seperately
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/*/wakeup/status
> > disabled
> > disabled
> > disabled
> > disabled
> > disabled
> > disabled
> > enabled
> > enabled
> > enabled
> > [root@localhost ~]# cat /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/*/*/wakeup/status
> > enabled
> > enabled
> > enabled
> > [root@localhost ~]#
> 
> 
> I think that it would be much much better to place wake-up attributes under
> corresponding PCI and PNP devices.
> Probably it is even better to link this code to PCI code, so PCI drivers will be aware of ACPI.
I like this idea, maxim. :)
And that's what we actually did about half a year ago.

Yi,
Please refer to http://bugzilla.kernel.org/show_bug.cgi?id=6892
and David's patch set here:
http://marc.info/?l=linux-mm-commits&m=117701595209299&w=2
http://marc.info/?l=linux-mm-commits&m=117701866524935&w=2
You can have a look at this thread as well:
http://marc.info/?l=linux-acpi&m=119982937409968&w=2

thanks,
Rui
> For example it will fix the 'EHCI instantly wakes up the system from S4' on my system, since here USB doesn't wake
> up anything from S4, and ACPI tables correctly show that.
> 
> If ehci driver was aware of that it could disable #PME on entrance to S4.
> And we even can reuse its 'wakeup' attribute, thus enabling wakeup automatically.
> 
> Going ever further, I think that it will be great to get rid of ACPI device tree, since
> most acpi devices are ether PCI of PNP ones.
> 
> Or, even better have a small ACPI tree, that will contain 'true' ACPI devices, like cpus
> thermal sensors, buttons, etc. 
>