eCTS: Add nested interrupt test (High->Low)

Add a nested interrupt test to eCTS. Higher priority IRQ is fired,
followed by lower priority IRQ. Handlers should be executed
sequentially.

P1               *-----*
                /       \
P2             /         *-----*
              /                 \
task_cts ----*                   *----
                 B     C A     D

BUG=chromium:653195
BRANCH=none
TEST=cts.py -m interrupt; make buildall

Change-Id: Ia9f1bf4205cefe8bdc11cc0aa3ad2057359b73ef
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/409611
Reviewed-by: Randall Spangler <rspangler@chromium.org>

4 files changed, 45 insertions, 5 deletions

diff --git a/cts/cts.py b/cts/cts.py
index b42f16c44b..82955436c7 100755
--- a/cts/cts.py
+++ b/cts/cts.py
@@ -33,7 +33,7 @@ CTS_COLOR_RED = '#fb7d7d'
 CTS_COLOR_GREEN = '#7dfb9f'
 DEFAULT_TH = 'stm32l476g-eval'
 DEFAULT_DUT = 'nucleo-f072rb'
-MAX_SUITE_TIME_SEC = 3
+MAX_SUITE_TIME_SEC = 5
 CTS_DEBUG_START = '[DEBUG]'
 CTS_DEBUG_END = '[DEBUG_END]'
 CTS_TEST_RESULT_DIR = '/tmp/cts'
diff --git a/cts/interrupt/cts.testlist b/cts/interrupt/cts.testlist
index 01d6c1b06e..6e0265ed60 100644
--- a/cts/interrupt/cts.testlist
+++ b/cts/interrupt/cts.testlist
@@ -25,6 +25,18 @@ CTS_TEST(test_task_disable_irq)
  */
 CTS_TEST(test_nested_interrupt_low_high)
 
+/* Test nested interrupt. Higher priority IRQ is fired, followed by
+ * lower priority IRQ. Handlers should be executed sequentially.
+ *
+ * P1               *-----*
+ *                 /       \
+ * P2             /         *-----*
+ *               /                 \
+ * task_cts ----*                   *----
+ *                  B     C A     D
+ */
+CTS_TEST(test_nested_interrupt_high_low)
+
 /*
  * Other ideas
  *
diff --git a/cts/interrupt/dut.c b/cts/interrupt/dut.c
index 9bf7eabde6..a04d5659d5 100644
--- a/cts/interrupt/dut.c
+++ b/cts/interrupt/dut.c
@@ -45,12 +45,15 @@ static int busy_loop(void)
 void cts_irq1(enum gpio_signal signal)
 {
 	state[state_index++] = 'B';
-	/* test some APIs */
+
 	got_interrupt = in_interrupt_context();
 
 	/* Wake up the CTS task */
 	if (wake_me_up)
 		task_wake(TASK_ID_CTS);
+
+	busy_loop();
+
 	state[state_index++] = 'C';
 }
 
@@ -82,7 +85,7 @@ enum cts_rc test_task_wait_event(void)
 	/* Sleep and wait for interrupt. This shouldn't time out. */
 	event = task_wait_event(CTS_INTERRUPT_TRIGGER_DELAY_US * 2);
 	if (event != TASK_EVENT_WAKE) {
-		CPRINTS("Woke up by 0x%08x", event);
+		CPRINTS("Woken up by unexpected event: 0x%08x", event);
 		return CTS_RC_FAILURE;
 	}
 	if (!got_interrupt) {
@@ -103,7 +106,7 @@ enum cts_rc test_task_disable_irq(void)
 	/* Sleep and wait for interrupt. This should time out. */
 	event = task_wait_event(CTS_INTERRUPT_TRIGGER_DELAY_US * 2);
 	if (event != TASK_EVENT_TIMER) {
-		CPRINTS("Woke up by 0x%08x", event);
+		CPRINTS("Woken up by unexpected event: 0x%08x", event);
 		return CTS_RC_FAILURE;
 	}
 	task_enable_irq(CTS_IRQ_NUMBER);
@@ -136,7 +139,7 @@ enum cts_rc test_nested_interrupt_low_high(void)
 
 	event = task_wait_event(CTS_INTERRUPT_TRIGGER_DELAY_US * 4);
 	if (event != TASK_EVENT_TIMER) {
-		CPRINTS("Woke up by 0x%08x", event);
+		CPRINTS("Woken up by unexpected event: 0x%08x", event);
 		return CTS_RC_FAILURE;
 	}
 	if (!got_interrupt) {
@@ -151,6 +154,24 @@ enum cts_rc test_nested_interrupt_low_high(void)
 	return CTS_RC_SUCCESS;
 }
 
+enum cts_rc test_nested_interrupt_high_low(void)
+{
+	uint32_t event;
+
+	event = task_wait_event(CTS_INTERRUPT_TRIGGER_DELAY_US * 4);
+	if (event != TASK_EVENT_TIMER) {
+		CPRINTS("Woken up by unexpected event: 0x%08x", event);
+		return CTS_RC_FAILURE;
+	}
+
+	if (memcmp(state, "BCAD", sizeof(state))) {
+		CPRINTS("State transition differs from expectation");
+		return CTS_RC_FAILURE;
+	}
+
+	return CTS_RC_SUCCESS;
+}
+
 #include "cts_testlist.h"
 
 void cts_task(void)
diff --git a/cts/interrupt/th.c b/cts/interrupt/th.c
index 87582490ed..0949faa8b2 100644
--- a/cts/interrupt/th.c
+++ b/cts/interrupt/th.c
@@ -54,6 +54,13 @@ enum cts_rc test_nested_interrupt_low_high(void)
 	return CTS_RC_SUCCESS;
 }
 
+enum cts_rc test_nested_interrupt_high_low(void)
+{
+	trigger_interrupt1();
+	trigger_interrupt2();
+	return CTS_RC_SUCCESS;
+}
+
 #include "cts_testlist.h"
 
 void cts_task(void)