[L] [PATCH 1/1] mei: mei-me: resume device in prepare

[Kai-Heng Feng]

From: Alexander Usyskin <alexander.usyskin at intel.com>

BugLink: https://bugs.launchpad.net/bugs/2035313

Asynchronous runtime resume is not possible while the system
is suspending.
The power management subsystem resumes the device only in the
suspend phase, not in the prepare phase.
Force resume device in prepare to allow drivers on mei bus
to communicate in their prepare callbacks.

Signed-off-by: Alexander Usyskin <alexander.usyskin at intel.com>
Reviewed-by: Tomas Winkler <tomas.winkler at intel.com>
Signed-off-by: Alan Previn <alan.previn.teres.alexis at intel.com>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230125082637.118970-2-alan.previn.teres.alexis@intel.com
(cherry picked from commit 907deab2afc86cf30a53c3a37c2277c984558e84)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/misc/mei/pci-me.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
index 7fafc1e60b8d..cab5db43864e 100644
--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -346,6 +346,12 @@ static void mei_me_remove(struct pci_dev *pdev)
 }
 
 #ifdef CONFIG_PM_SLEEP
+static int mei_me_pci_prepare(struct device *device)
+{
+	pm_runtime_resume(device);
+	return 0;
+}
+
 static int mei_me_pci_suspend(struct device *device)
 {
 	struct pci_dev *pdev = to_pci_dev(device);
@@ -402,7 +408,17 @@ static int mei_me_pci_resume(struct device *device)
 
 	return 0;
 }
-#endif /* CONFIG_PM_SLEEP */
+
+static void mei_me_pci_complete(struct device *device)
+{
+	pm_runtime_suspend(device);
+}
+#else /* CONFIG_PM_SLEEP */
+
+#define mei_me_pci_prepare NULL
+#define mei_me_pci_complete NULL
+
+#endif /* !CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM
 static int mei_me_pm_runtime_idle(struct device *device)
@@ -505,6 +521,8 @@ static inline void mei_me_unset_pm_domain(struct mei_device *dev)
 }
 
 static const struct dev_pm_ops mei_me_pm_ops = {
+	.prepare = mei_me_pci_prepare,
+	.complete = mei_me_pci_complete,
 	SET_SYSTEM_SLEEP_PM_OPS(mei_me_pci_suspend,
 				mei_me_pci_resume)
 	SET_RUNTIME_PM_OPS(
-- 
2.34.1