soundwire: intel: reset pm_runtime status during system resume

The system resume does the entire bus re-initialization and brings it
to full-power. If the device was pm_runtime suspended, there is no
need to run the pm_runtime resume sequence after the system runtime.

Follow the documentation from runtime_pm.rst, and conditionally
disable, set_active and re-enable the device on system resume.

Note that pm_runtime_suspended() is used instead of
pm_runtime_status_suspended() so that we can deal with the case where
pm_runtime is disabled.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-3-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/intel.c

@@ -1434,6 +1434,12 @@ static int intel_suspend(struct device *dev)
 		return 0;
 	}
 
+	if (pm_runtime_suspended(dev)) {
+		dev_dbg(dev, "%s: pm_runtime status: suspended\n", __func__);
+
+		return 0;
+	}
+
 	ret = sdw_cdns_enable_interrupt(cdns, false);
 	if (ret < 0) {
 		dev_err(dev, "cannot disable interrupts on suspend\n");
@@ -1494,6 +1500,16 @@ static int intel_resume(struct device *dev)
 		return 0;
 	}
 
+	if (pm_runtime_suspended(dev)) {
+		dev_dbg(dev, "%s: pm_runtime status was suspended, forcing active\n", __func__);
+
+		/* follow required sequence from runtime_pm.rst */
+		pm_runtime_disable(dev);
+		pm_runtime_set_active(dev);
+		pm_runtime_mark_last_busy(dev);
+		pm_runtime_enable(dev);
+	}
+
 	ret = intel_init(sdw);
 	if (ret) {
 		dev_err(dev, "%s failed: %d", __func__, ret);