diff mbox series

[11/13] soundwire: intel_init: handle power rail dependencies for clock stop mode

Message ID 20200721203723.18305-12-yung-chuan.liao@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series soundwire: intel: add power management support | expand

Commit Message

Bard Liao July 21, 2020, 8:37 p.m. UTC 
From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

When none of the clock stop quirks is specified, the Master IP will
assume the context is preserved and will not reset the Bus and restart
enumeration. Due to power rail dependencies, the HDaudio controller
needs to remain powered and prevented from executing its pm_runtime
suspend routine.

This choice of course has a power impact, and this mode should only be
selected when latency requirements are critical or the parent device
can enter D0ix modes.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/soundwire/intel_init.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c
index 96c9af15c308..c0fddf76a6dc 100644
--- a/drivers/soundwire/intel_init.c
+++ b/drivers/soundwire/intel_init.c
@@ -14,6 +14,7 @@ 
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/soundwire/sdw_intel.h>
+#include <linux/pm_runtime.h>
 #include "cadence_master.h"
 #include "intel.h"
 
@@ -72,6 +73,9 @@  static int sdw_intel_cleanup(struct sdw_intel_ctx *ctx)
 			pm_runtime_disable(&link->pdev->dev);
 			platform_device_unregister(link->pdev);
 		}
+
+		if (!link->clock_stop_quirks)
+			pm_runtime_put_noidle(link->dev);
 	}
 
 	return 0;
@@ -337,6 +341,16 @@  sdw_intel_startup_controller(struct sdw_intel_ctx *ctx)
 			continue;
 
 		intel_master_startup(link->pdev);
+
+		if (!link->clock_stop_quirks) {
+			/*
+			 * we need to prevent the parent PCI device
+			 * from entering pm_runtime suspend, so that
+			 * power rails to the SoundWire IP are not
+			 * turned off.
+			 */
+			pm_runtime_get_noresume(link->dev);
+		}
 	}
 
 	return 0;