Patch "mei: me: allow runtime pm for platform with D0i3" has been added to the 4.15-stable tree

Patch "mei: me: allow runtime pm for platform with D0i3" has been added to the 4.15-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mei: me: allow runtime pm for platform with D0i3

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mei-me-allow-runtime-pm-for-platform-with-d0i3.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From cc365dcf0e56271bedf3de95f88922abe248e951 Mon Sep 17 00:00:00 2001
From: Tomas Winkler <tomas.winkler@intel.com>
Date: Tue, 2 Jan 2018 12:01:41 +0200
Subject: mei: me: allow runtime pm for platform with D0i3

From: Tomas Winkler <tomas.winkler@intel.com>

commit cc365dcf0e56271bedf3de95f88922abe248e951 upstream.

>>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: 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>

---
 drivers/misc/mei/pci-me.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- 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 *
 	 */
 	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");
 


Patches currently in stable-queue which might be from tomas.winkler@intel.com are

queue-4.15/mei-me-allow-runtime-pm-for-platform-with-d0i3.patch