mei: me: allow runtime pm for platform with D0i3

>From the pci power documentation:
"The driver itself should not call pm_runtime_allow(), though. Instead,
it should let user space or some platform-specific code do that (user space
can do it via sysfs as stated above)..."

However, the S0ix residency cannot be reached without MEI device getting
into low power state. Hence, for mei devices that support D0i3, it's better
to make runtime power management mandatory and not rely on the system
integration such as udev rules.
This policy cannot be applied globally as some older platforms
were found to have broken power management.

Cc: <stable@vger.kernel.org> v4.13+
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
index f4f17552c9b804c3667c6d3a7c702ac30a4eaac0..4a0ccda4d04b9a898c4cd3163ada9d94f581242e 100644 (file)
--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -238,8 +238,11 @@ static int mei_me_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
         */
        mei_me_set_pm_domain(dev);
 
-       if (mei_pg_is_enabled(dev))
+       if (mei_pg_is_enabled(dev)) {
                pm_runtime_put_noidle(&pdev->dev);
+               if (hw->d0i3_supported)
+                       pm_runtime_allow(&pdev->dev);
+       }
 
        dev_dbg(&pdev->dev, "initialization successful.\n");