[PATCH 4.9 37/39] HID: intel_ish-hid: ipc: register more pm callbacks to support hibernation

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Even Xu <even.xu@intel.com>

commit ebeaa367548e9e92dd9374b9464ff6e7d157117b upstream.

Current ISH driver only registers suspend/resume PM callbacks which don't
support hibernation (suspend to disk). Basically after hiberation, the ISH
can't resume properly and user may not see sensor events (for example: screen
		rotation may not work).

User will not see a crash or panic or anything except the following message
in log:

	hid-sensor-hub 001F:8086:22D8.0001: timeout waiting for response from ISHTP device

So this patch adds support for S4/hiberbation to ISH by using the
SIMPLE_DEV_PM_OPS() MACRO instead of struct dev_pm_ops directly. The suspend
and resume functions will now be used for both suspend to RAM and hibernation.

If power management is disabled, SIMPLE_DEV_PM_OPS will do nothing, the suspend
and resume related functions won't be used, so mark them as __maybe_unused to
clarify that this is the intended behavior, and remove #ifdefs for power
management.

Cc: stable@vger.kernel.org
Signed-off-by: Even Xu <even.xu@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hid/intel-ish-hid/ipc/pci-ish.c |   22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

--- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
+++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
@@ -202,8 +202,7 @@ static void ish_remove(struct pci_dev *p
 	kfree(ishtp_dev);
 }
 
-#ifdef CONFIG_PM
-static struct device *ish_resume_device;
+static struct device __maybe_unused *ish_resume_device;
 
 /**
  * ish_resume_handler() - Work function to complete resume
@@ -214,7 +213,7 @@ static struct device *ish_resume_device;
  * in that case a simple resume message is enough, others we need
  * a reset sequence.
  */
-static void ish_resume_handler(struct work_struct *work)
+static void __maybe_unused ish_resume_handler(struct work_struct *work)
 {
 	struct pci_dev *pdev = to_pci_dev(ish_resume_device);
 	struct ishtp_device *dev = pci_get_drvdata(pdev);
@@ -245,7 +244,7 @@ static void ish_resume_handler(struct wo
  *
  * Return: 0 to the pm core
  */
-static int ish_suspend(struct device *device)
+static int __maybe_unused ish_suspend(struct device *device)
 {
 	struct pci_dev *pdev = to_pci_dev(device);
 	struct ishtp_device *dev = pci_get_drvdata(pdev);
@@ -271,7 +270,7 @@ static int ish_suspend(struct device *de
 	return 0;
 }
 
-static DECLARE_WORK(resume_work, ish_resume_handler);
+static __maybe_unused DECLARE_WORK(resume_work, ish_resume_handler);
 /**
  * ish_resume() - ISH resume callback
  * @device:	device pointer
@@ -280,7 +279,7 @@ static DECLARE_WORK(resume_work, ish_res
  *
  * Return: 0 to the pm core
  */
-static int ish_resume(struct device *device)
+static int __maybe_unused ish_resume(struct device *device)
 {
 	struct pci_dev *pdev = to_pci_dev(device);
 	struct ishtp_device *dev = pci_get_drvdata(pdev);
@@ -294,21 +293,14 @@ static int ish_resume(struct device *dev
 	return 0;
 }
 
-static const struct dev_pm_ops ish_pm_ops = {
-	.suspend = ish_suspend,
-	.resume = ish_resume,
-};
-#define ISHTP_ISH_PM_OPS	(&ish_pm_ops)
-#else
-#define ISHTP_ISH_PM_OPS	NULL
-#endif /* CONFIG_PM */
+static SIMPLE_DEV_PM_OPS(ish_pm_ops, ish_suspend, ish_resume);
 
 static struct pci_driver ish_driver = {
 	.name = KBUILD_MODNAME,
 	.id_table = ish_pci_tbl,
 	.probe = ish_probe,
 	.remove = ish_remove,
-	.driver.pm = ISHTP_ISH_PM_OPS,
+	.driver.pm = &ish_pm_ops,
 };
 
 module_pci_driver(ish_driver);