Add a plugin for amdgpu tuning of the panel_power_savings attribute

profiles/accelerator-performance/tuned.conf

@@ -62,3 +62,6 @@ sched_min_granularity_ns = 10000000
 # and reduces their over-scheduling. Synchronous workloads will still
 # have immediate wakeup/sleep latencies.
 sched_wakeup_granularity_ns = 15000000
+
+[video]
+panel_power_savings=0

profiles/balanced/tuned.conf

@@ -22,6 +22,7 @@ timeout=10
 
 [video]
 radeon_powersave=dpm-balanced, auto
+panel_power_savings=0
 
 [disk]
 # Comma separated list of devices, all devices if commented out.

profiles/latency-performance/tuned.conf

@@ -35,3 +35,6 @@ vm.dirty_background_ratio=3
 # 100 tells the kernel to aggressively swap processes out of physical memory
 # and move them to swap cache
 vm.swappiness=10
+
+[video]
+panel_power_savings=0

profiles/powersave/tuned.conf

@@ -22,6 +22,7 @@ timeout=10
 
 [video]
 radeon_powersave=dpm-battery, auto
+panel_power_savings=3
 
 [disk]
 # Comma separated list of devices, all devices if commented out.

profiles/throughput-performance/tuned.conf

@@ -73,3 +73,6 @@ type=sysctl
 uname_regex=aarch64
 cpuinfo_regex=${thunderx_cpuinfo_regex}
 kernel.numa_balancing=0
+
+[video]
+panel_power_savings=0

tuned/plugins/plugin_video.py

@@ -11,9 +11,10 @@
 class VideoPlugin(base.Plugin):
 	"""
 	`video`::
-
-	Sets various powersave levels on video cards. Currently, only the
-	Radeon cards are supported. The powersave level can be specified
+
+	Sets various power saving features on video cards.
+	Radeon cards are supported.
+	The powersave level can be specified
 	by using the [option]`radeon_powersave` option. Supported values are:
 	+
 	--
@@ -40,17 +41,27 @@ class VideoPlugin(base.Plugin):
 	radeon_powersave=high
 	----
 	====
+
+	Mobile hardware with amdgpu driven eDP panels can be configured
+	with the [option]`panel_power_savings` option.
+	This accepts a value range from 0 to 4, where 4 is the highest power savings
+	but will trade off color accuracy.
 	"""
 
+	def __init__(self, *args, **kwargs):
+		super(VideoPlugin, self).__init__(*args, **kwargs)
+
 	def _init_devices(self):
 		self._devices_supported = True
 		self._free_devices = set()
 		self._assigned_devices = set()
 
-		# FIXME: this is a blind shot, needs testing
-		for device in self._hardware_inventory.get_devices("drm").match_sys_name("card*").match_property("DEVTYPE", "drm_minor"):
-			self._free_devices.add(device.sys_name)
-
+		# Add any radeon and amdgpu hardware with /any/ supported attributes present
+		for device in self._hardware_inventory.get_devices("drm").match_sys_name("card*-*"):
+			attrs = self._files(device.sys_name)
+			for attr in attrs:
+				if os.path.exists(attrs[attr]):
+					self._free_devices.add(device.sys_name)
 		self._cmd = commands()
 
 	def _get_device_objects(self, devices):
@@ -60,6 +71,7 @@ def _get_device_objects(self, devices):
 	def _get_config_options(self):
 		return {
 			"radeon_powersave" : None,
+			"panel_power_savings": None,
 		}
 
 	def _instance_init(self, instance):
@@ -69,20 +81,42 @@ def _instance_init(self, instance):
 	def _instance_cleanup(self, instance):
 		pass
 
-	def _radeon_powersave_files(self, device):
+	def _files(self, device):
 		return {
 			"method" : "/sys/class/drm/%s/device/power_method" % device,
 			"profile": "/sys/class/drm/%s/device/power_profile" % device,
-			"dpm_state": "/sys/class/drm/%s/device/power_dpm_state" % device
+			"dpm_state": "/sys/class/drm/%s/device/power_dpm_state" % device,
+			"panel_power_savings": "/sys/class/drm/%s/amdgpu/panel_power_savings" % device,
 		}
 
+	def apply_panel_power_saving_target(self, device, target, sim=False):
+		"""Apply the target value to the panel_power_savings file if it doesn't already have it"""
+
+		# if we don't have the file, we might be radeon not amdgpu
+		if not os.path.exists(self._files(device)["panel_power_savings"]):
+			return None
+
+		# make sure the value is different (avoids unnecessary kernel modeset)
+		current = int(self._get_panel_power_savings(device))
+		if current == target:
+			log.info(
+				"panel_power_savings for %s already %s" % (device, target)
+			)
+			return target
+
+		# flush it out
+		log.info("%s panel_power_savings -> %s" % (device, target))
+		if sim or self._cmd.write_to_file(self._files(device)["panel_power_savings"], target):
+			return target
+		return None
+
 	@command_set("radeon_powersave", per_device=True)
 	def _set_radeon_powersave(self, value, device, sim, remove):
-		sys_files = self._radeon_powersave_files(device)
+		sys_files = self._files(device)
 		va = str(re.sub(r"(\s*:\s*)|(\s+)|(\s*;\s*)|(\s*,\s*)", " ", value)).split()
 		if not os.path.exists(sys_files["method"]):
 			if not sim:
-				log.warn("radeon_powersave is not supported on '%s'" % device)
+				log.debug("radeon_powersave is not supported on '%s'" % device)
 				return None
 		for v in va:
 			if v in ["default", "auto", "low", "mid", "high"]:
@@ -114,7 +148,10 @@ def _set_radeon_powersave(self, value, device, sim, remove):
 
 	@command_get("radeon_powersave")
 	def _get_radeon_powersave(self, device, ignore_missing = False):
-		sys_files = self._radeon_powersave_files(device)
+		sys_files = self._files(device)
+		if not os.path.exists(sys_files["method"]):
+			log.debug("radeon_powersave is not supported on '%s'" % device)
+			return None
 		method = self._cmd.read_file(sys_files["method"], no_error=ignore_missing).strip()
 		if method == "profile":
 			return self._cmd.read_file(sys_files["profile"]).strip()
@@ -124,3 +161,26 @@ def _get_radeon_powersave(self, device, ignore_missing = False):
 			return "dpm-" + self._cmd.read_file(sys_files["dpm_state"]).strip()
 		else:
 			return None
+
+	@command_set("panel_power_savings", per_device=True)
+	def _set_panel_power_savings(self, value, device, sim, remove):
+		"""Set the panel_power_savings value"""
+		try:
+			value = int(value, 10)
+		except ValueError:
+			log.warn("Invalid value %s for panel_power_savings" % value)
+			return None
+		if value in range(0, 5):
+			return self.apply_panel_power_saving_target(device, value, sim)
+		else:
+			log.warn("Invalid value %s for panel_power_savings" % value)
+		return None
+
+	@command_get("panel_power_savings")
+	def _get_panel_power_savings(self, device, ignore_missing=False):
+		"""Get the current panel_power_savings value"""
+		if not os.path.exists(self._files(device)["panel_power_savings"]):
+			log.debug("panel_power_savings is not supported on '%s'" % device)
+			return None
+		fname = self._files(device)["panel_power_savings"]
+		return self._cmd.read_file(fname, no_error=ignore_missing).strip()