lib/igt_pm: Lib for power management

Move power management related code to a separate library.
Initially this is done only for workarounds that apply to external
components.  Modify the users of such workarounds accordingly.
This currently involves HD audio and SATA link power management.
For SATA link PM there's also code to save the previous settings,
to allow for resetting the values after we've finished testing.

Signed-off-by: David Weinehall <david.weinehall@intel.com>
Reviewed-by: Marius Vlad <marius.c.vlad@intel.com>
Signed-off-by: Marius Vlad <marius.c.vlad@intel.com>

tests/pm_lpsp.c

@@ -31,29 +31,6 @@
 #include <unistd.h>
 
 
-/* We know that if we don't enable audio runtime PM, snd_hda_intel will never
- * release its power well refcount, and we'll never reach the LPSP sate. OTOH
- * there's no guarantee that it will release the power well if we enable runtime
- * PM, but at least we can try.  We don't have any assertions since the user may
- * not even have snd_hda_intel loaded, which is not a problem. */
-static void disable_audio_runtime_pm(void)
-{
-	int fd;
-
-	fd = open("/sys/module/snd_hda_intel/parameters/power_save", O_WRONLY);
-	if (fd >= 0) {
-		igt_assert_eq(write(fd, "1\n", 2), 2);
-		close(fd);
-	}
-	fd = open("/sys/bus/pci/devices/0000:00:03.0/power/control", O_WRONLY);
-	if (fd >= 0) {
-		igt_assert_eq(write(fd, "auto\n", 5), 5);
-		close(fd);
-	}
-	/* Give some time for it to react. */
-	sleep(1);
-}
-
 static bool supports_lpsp(uint32_t devid)
 {
 	return IS_HASWELL(devid) || IS_BROADWELL(devid);
@@ -227,7 +204,7 @@ igt_main
 			drm_connectors[i] = drmModeGetConnectorCurrent(drm_fd,
 							drm_res->connectors[i]);
 
-		disable_audio_runtime_pm();
+		igt_pm_enable_audio_runtime_pm();
 
 		igt_require(supports_lpsp(devid));
 

tests/pm_rpm.c

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2013 Intel Corporation
+ * Copyright © 2013, 2015 Intel Corporation
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -109,6 +109,8 @@ struct modeset_params lpsp_mode_params;
 struct modeset_params non_lpsp_mode_params;
 struct modeset_params *default_mode_params;
 
+static int8_t *pm_data = NULL;
+
 /* If the read fails, then the machine doesn't support PC8+ residencies. */
 static bool supports_pc8_plus_residencies(void)
 {
@@ -685,41 +687,13 @@ static void setup_pc8(void)
 	has_pc8 = true;
 }
 
-/* If we want to actually reach PC8+ states, we need to properly configure all
- * the devices on the system to allow this. This function will try to setup the
- * things we know we need, but won't scream in case anything fails: we don't
- * know which devices are present on your machine, so we can't really expect
- * anything, just try to help with the more common problems. */
-static void setup_non_graphics_runtime_pm(void)
-{
-	int fd, i;
-	char *file_name;
-
-	/* Disk runtime PM policies. */
-	file_name = malloc(PATH_MAX);
-	for (i = 0; ; i++) {
-
-		snprintf(file_name, PATH_MAX,
-			 "/sys/class/scsi_host/host%d/link_power_management_policy",
-			 i);
-
-		fd = open(file_name, O_WRONLY);
-		if (fd < 0)
-			break;
-
-		igt_assert(write(fd, "min_power\n", 10) == 10);
-		close(fd);
-	}
-	free(file_name);
-}
-
 static void setup_environment(void)
 {
 	drm_fd = drm_open_driver_master(DRIVER_INTEL);
 
 	init_mode_set_data(&ms_data);
 
-	setup_non_graphics_runtime_pm();
+	pm_data = igt_pm_enable_sata_link_power_management();
 
 	has_runtime_pm = igt_setup_runtime_pm();
 	setup_pc8();
@@ -728,11 +702,17 @@ static void setup_environment(void)
 	igt_info("PC8 residency support: %d\n", has_pc8);
 
 	igt_require(has_runtime_pm);
+}
 
+static void restore_environment(void)
+{
+	igt_pm_restore_sata_link_power_management(pm_data);
+	free(pm_data);
 }
 
 static void teardown_environment(void)
 {
+	restore_environment();
 	fini_mode_set_data(&ms_data);
 	drmClose(drm_fd);
 	close(msr_fd);