lib/igt_aux: Improve documentation for igt_system_suspend_autoresume()

While at it fix the order of states for consistency.

Suggested by Daniel.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 51 insertions, 6 deletions

diff --git a/lib/igt_aux.c b/lib/igt_aux.c
index f225c2f6..421f6d4e 100644
--- a/lib/igt_aux.c
+++ b/lib/igt_aux.c
@@ -628,8 +628,8 @@ void igt_cleanup_aperture_trashers(void)
 
 static const char *suspend_state_name[] = {
 	[SUSPEND_STATE_FREEZE] = "freeze",
-	[SUSPEND_STATE_MEM] = "mem",
 	[SUSPEND_STATE_STANDBY] = "standby",
+	[SUSPEND_STATE_MEM] = "mem",
 	[SUSPEND_STATE_DISK] = "disk",
 };
 
@@ -744,11 +744,22 @@ static uint32_t get_supported_suspend_states(int power_dir)
 
 /**
  * igt_system_suspend_autoresume:
+ * @state: an #igt_suspend_state, the target suspend state
+ * @test: an #igt_suspend_test, test point at which to complete the suspend
+ *	  cycle
+ *
+ * Execute a system suspend cycle targeting the given @state optionally
+ * completing the cycle at the given @test point and automaically wake up
+ * again. Waking up is either achieved using the RTC wake-up alarm for a full
+ * suspend cycle or a kernel timer for a suspend test cycle. The kernel timer
+ * delay for a test cycle can be configured by the suspend.pm_test_delay
+ * kernel parameter (5 sec by default).
  *
- * Execute a system suspend (to idle, memory, disk) cycle optionally
- * completing the cycle at a given test point and automaically wake up again.
- * Waking up is either achieved using the RTC wake-up alarm for a full suspend
- * cycle or a kernel timer for a suspend test cycle.
+ * #SUSPEND_TEST_NONE specifies a full suspend cycle.
+ * The #SUSPEND_TEST_FREEZER..#SUSPEND_TEST_CORE test points can make it
+ * possible to collect error logs in case a full suspend cycle would prevent
+ * this by hanging the machine, or they can provide an idea of the faulty
+ * component by comparing fail/no-fail results at different test points.
  *
  * This is very handy for implementing any kind of suspend/resume test.
  */
diff --git a/lib/igt_aux.h b/lib/igt_aux.h
index 39fd8ea6..d30196b9 100644
--- a/lib/igt_aux.h
+++ b/lib/igt_aux.h
@@ -116,15 +116,48 @@ void igt_cleanup_aperture_trashers(void);
 
 /* suspend/hibernate and auto-resume system */
 
+/**
+ *  igt_suspend_state:
+ *  @SUSPEND_STATE_FREEZE: suspend-to-idle target state, aka S0ix or freeze,
+ *			   first non-hibernation state
+ *  @SUSPEND_STATE_STANDBY: standby target state, aka S1, second
+ *			    non-hibernation state
+ *  @SUSPEND_STATE_MEM: suspend-to-mem target state aka S3, third
+ *			non-hibernation state
+ *  @SUSPEND_STATE_DISK: suspend-to-disk target state, aka S4 or hibernation
+ *
+ *  Target suspend states used with igt_system_suspend_autoresume().
+ *  See /sys/power/state for the available states on a given machine.
+ */
 enum igt_suspend_state {
 	SUSPEND_STATE_FREEZE,
-	SUSPEND_STATE_MEM,
 	SUSPEND_STATE_STANDBY,
+	SUSPEND_STATE_MEM,
 	SUSPEND_STATE_DISK,
 
+	/*< private >*/
 	SUSPEND_STATE_NUM,
 };
 
+/**
+ * igt_suspend_test:
+ * @SUSPEND_TEST_NONE: no testing, perform a full suspend/resume cycle
+ * @SUSPEND_TEST_FREEZER: complete cycle after freezing all freezable threads
+ * @SUSPEND_TEST_DEVICES: complete cycle after the above step and suspending
+ *			  devices (before calling the drivers' suspend late and
+ *			  no_irq hooks). Platform and system devices are not
+ *			  suspended here, see #SUSPEND_TEST_CORE.
+ * @SUSPEND_TEST_PLATFORM: complete cycle after all the above steps and calling
+ *			   the ACPI platform global control methods (applies
+ *			   only with /sys/power/disk set to platform)
+ * @SUSPEND_TEST_PROCESSORS: complete cycle after all the above steps and
+ *			     disabling non-boot CPUs
+ * @SUSPEND_TEST_CORE: complete cycle after all the above steps and suspending
+ *		       platform and system devices
+ *
+ * Test points used with igt_system_suspend_autoresume(). Specifies if and where
+ * the suspend sequence is to be terminated.
+ */
 enum igt_suspend_test {
 	SUSPEND_TEST_NONE,
 	SUSPEND_TEST_FREEZER,
@@ -133,6 +166,7 @@ enum igt_suspend_test {
 	SUSPEND_TEST_PROCESSORS,
 	SUSPEND_TEST_CORE,
 
+	/*< private >*/
 	SUSPEND_TEST_NUM,
 };