[PATCH 3.16 026/125] mei: dont schedule suspend in pm idle

From: Greg Kroah-Hartman
Date: Wed Sep 03 2014 - 19:17:25 EST


3.16-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>

commit d5d83f8abea13d0b50ee762276c6c900d1946264 upstream.

Calling pm_schedule_suspend from the runtime pm idle callback
may reschedule existing timer, thus in case of frequent runtime
rpm idle call the suspend maybe starved.
Instead we call pm_runtime_autosuspend which is checking if the
timer is already charged.

An example is monitoring device pci config space.
Pci config sysfs handlers calls pci_config_pm_runtime_put/get
helpers which in turns calls to device idle callback

Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/misc/mei/pci-me.c | 2 +-
drivers/misc/mei/pci-txe.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -369,7 +369,7 @@ static int mei_me_pm_runtime_idle(struct
if (!dev)
return -ENODEV;
if (mei_write_is_idle(dev))
- pm_schedule_suspend(device, MEI_ME_RPM_TIMEOUT * 2);
+ pm_runtime_autosuspend(device);

return -EBUSY;
}
--- a/drivers/misc/mei/pci-txe.c
+++ b/drivers/misc/mei/pci-txe.c
@@ -306,7 +306,7 @@ static int mei_txe_pm_runtime_idle(struc
if (!dev)
return -ENODEV;
if (mei_write_is_idle(dev))
- pm_schedule_suspend(device, MEI_TXI_RPM_TIMEOUT * 2);
+ pm_runtime_autosuspend(device);

return -EBUSY;
}


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