i2c runtime suspend and system wide suspend
Subsystems (2)
The i2c-core driver mixes runtime suspend and system wide suspend, in that, during a system wide suspend, it skips calling ->suspend if the device is runtime suspended.
I have an interrupt controller running over the i2c bus and that driver is oblivious of the runtime pm framework, IOW, it doesn't do any runtime pm calls. CONFIG_RUNTIME_PM is enabled however (for some other bus drivers). The issue I am facing is that all such i2c devices are assumed runtime suspended and the ->suspend for these devices is not invoked during systemwide suspend.
Looking around in pci and platform busses, they don't skip calling the ->suspend callback, actually, they dont check if the device is runtime suspended.
The question is, why do we have this special check in i2c bus driver?
Pasted below is the relevant commit.
commit 2f60ba706bd9af84c4eab704243b262e69556f2e
i2c: Fix bus-level power management callbacks
There are three issues with the i2c bus type's power management callbacks at the moment. ....
....
....
.... Finally, the system sleep PM
(ie. suspend/resume) callbacks don't check if the device has been already suspended at run time, in which case they should skip suspending it. Also, it looks like the i2c bus type can use the generic subsystem-level runtime PM callbacks.
For these reasons, rework the system sleep PM callbacks provided by the i2c bus type to handle hibernation correctly and to invoke the "legacy" callbacks for drivers that provide them. In addition to that make the i2c bus type use the generic subsystem-level runtime PM callbacks.
Thanks,
Abhijeet
--
Sent by an employee of Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum.
Quoted 10 lines · Abhijeet Dharmapurikar
The i2c-core driver mixes runtime suspend and system wide suspend, in that, during a system wide suspend, it skips calling ->suspend if the device is runtime suspended.
I have an interrupt controller running over the i2c bus and that driver is oblivious of the runtime pm framework, IOW, it doesn't do any runtime pm calls.
CONFIG_RUNTIME_PMis enabled however (for some other bus drivers). The issue I am facing is that all such i2c devices are assumed runtime suspended and the ->suspend for these devices is not invoked during systemwide suspend.
This was discussed on linux-pm recently. Rafael had a fix, I'm don't know whether it's applied yet:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029567.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029596.html
Also relevant:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029600.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029658.html
Quoted 13 lines · Rabin Vincent
Quoted 10 lines · Abhijeet Dharmapurikar
The i2c-core driver mixes runtime suspend and system wide suspend, in that, during a system wide suspend, it skips calling ->suspend if the device is runtime suspended.
I have an interrupt controller running over the i2c bus and that driver is oblivious of the runtime pm framework, IOW, it doesn't do any runtime pm calls.
CONFIG_RUNTIME_PMis enabled however (for some other bus drivers). The issue I am facing is that all such i2c devices are assumed runtime suspended and the ->suspend for these devices is not invoked during systemwide suspend.
Quoted 5 lines
This was discussed on linux-pm recently. Rafael had a fix, I'm don't know whether it's applied yet:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029567.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029596.html
Yes, the fix is already in the Linus' tree:
f08f5a0 PM / Runtime: Fix pm_runtime_suspended()
Quoted 4 lines
Also relevant:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029600.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029658.html
I'm not sure what happened to the last patch. Is there a new version? If so, is it going to be pushed through the i2c tree, or should I take it?
Rafael
Quoted 6 lines · Rafael J. Wysocki
Quoted 1 line · Rabin Vincent
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029658.html
I'm not sure what happened to the last patch. Is there a new version? If so, is it going to be pushed through the i2c tree, or should I take it?
Jean appears to be on holiday for the Christmas vacation. I do have a new version which I'll post later today. Since it depends on the patch protoyping the generic API calls which the SPI patch also depends on it'd probably be best to merge via your tree.
Quoted 6 lines · Rafael J. Wysocki
Quoted 1 line · Rabin Vincent
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029658.html
I'm not sure what happened to the last patch. Is there a new version? If so, is it going to be pushed through the i2c tree, or should I take it?
Jean appears to be on holiday for the Christmas vacation. I do have a new version which I'll post later today. Since it depends on the patch protoyping the generic API calls which the SPI patch also depends on it'd probably be best to merge via your tree.
Quoted 13 lines · Rabin Vincent
Quoted 10 lines · Abhijeet Dharmapurikar
The i2c-core driver mixes runtime suspend and system wide suspend, in that, during a system wide suspend, it skips calling ->suspend if the device is runtime suspended.
I have an interrupt controller running over the i2c bus and that driver is oblivious of the runtime pm framework, IOW, it doesn't do any runtime pm calls.
CONFIG_RUNTIME_PMis enabled however (for some other bus drivers). The issue I am facing is that all such i2c devices are assumed runtime suspended and the ->suspend for these devices is not invoked during systemwide suspend.
Quoted 5 lines
This was discussed on linux-pm recently. Rafael had a fix, I'm don't know whether it's applied yet:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029567.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029596.html
Yes, the fix is already in the Linus' tree:
f08f5a0 PM / Runtime: Fix pm_runtime_suspended()
Quoted 4 lines
Also relevant:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029600.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029658.html
I'm not sure what happened to the last patch. Is there a new version? If so, is it going to be pushed through the i2c tree, or should I take it?
Rafael
Quoted 10 lines · Abhijeet Dharmapurikar
The i2c-core driver mixes runtime suspend and system wide suspend, in that, during a system wide suspend, it skips calling ->suspend if the device is runtime suspended.
I have an interrupt controller running over the i2c bus and that driver is oblivious of the runtime pm framework, IOW, it doesn't do any runtime pm calls.
CONFIG_RUNTIME_PMis enabled however (for some other bus drivers). The issue I am facing is that all such i2c devices are assumed runtime suspended and the ->suspend for these devices is not invoked during systemwide suspend.
This was discussed on linux-pm recently. Rafael had a fix, I'm don't know whether it's applied yet:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029567.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029596.html
Also relevant:
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029600.html
https://lists.linux-foundation.org/pipermail/linux-pm/2010-December/029658.html