panicinfo: fix panicinfo double report

Panicinfo is double report due to the panic flags is reset
whenever a hard-reset triggered. This makes AP thinks there
is a new panic happened, and reports it to the crashmon.

We've seen a lot of crash reports due to the false alarms.
The solution is recording the panic flags across hard-reset
so we won't keep alarming the old panicinfo.

BUG=b:181108236
TEST=1)test that on juniper with new EC RO/RW, and AP reboot
       won't cause the EC alarming a new panicinfo.
     2)test that on juniper with soft-sync RW, and old RO, and
       AP reboot won't cause the EC alarm a new panicinfo
BRANCH=kukui

Change-Id: I6e0c33a1fcf210d9aa03ebd1cd79b84a7744c386
Signed-off-by: Eric Yilun Lin <yllin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2721327
Reviewed-by: Ting Shen <phoenixshen@chromium.org>

3 files changed, 25 insertions, 5 deletions

diff --git a/chip/lm4/system.c b/chip/lm4/system.c
index 75e7d556ec..bdb15d3861 100644
--- a/chip/lm4/system.c
+++ b/chip/lm4/system.c
@@ -25,7 +25,8 @@ enum hibdata_index {
 #ifdef CONFIG_SOFTWARE_PANIC
 	HIBDATA_INDEX_SAVED_PANIC_REASON,   /* Saved panic reason */
 	HIBDATA_INDEX_SAVED_PANIC_INFO,     /* Saved panic data */
-	HIBDATA_INDEX_SAVED_PANIC_EXCEPTION /* Saved panic exception code */
+	HIBDATA_INDEX_SAVED_PANIC_EXCEPTION,/* Saved panic exception code */
+	HIBDATA_INDEX_SAVED_PANIC_FLAGS,    /* Saved panic flags */
 #endif
 };
 
@@ -439,7 +440,7 @@ void system_pre_init(void)
 	uint32_t hibctl;
 #ifdef CONFIG_SOFTWARE_PANIC
 	uint32_t reason, info;
-	uint8_t exception;
+	uint8_t exception, panic_flags;
 #endif
 
 	/*
@@ -502,11 +503,15 @@ void system_pre_init(void)
 	reason = hibdata_read(HIBDATA_INDEX_SAVED_PANIC_REASON);
 	info = hibdata_read(HIBDATA_INDEX_SAVED_PANIC_INFO);
 	exception = hibdata_read(HIBDATA_INDEX_SAVED_PANIC_EXCEPTION);
+	panic_flags = hibdata_read(HIBDATA_INDEX_SAVED_PANIC_FLAGS);
+
 	if (reason || info || exception) {
 		panic_set_reason(reason, info, exception);
+		panic_get_data()->flags = panic_flags;
 		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_REASON, 0);
 		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_INFO, 0);
 		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_EXCEPTION, 0);
+		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_FLAGS, 0);
 	}
 #endif
 
@@ -544,13 +549,16 @@ void system_reset(int flags)
 	if (flags & SYSTEM_RESET_HARD) {
 #ifdef CONFIG_SOFTWARE_PANIC
 		uint32_t reason, info;
-		uint8_t exception;
+		uint8_t exception, panic_flags;
+
+		panic_flags = panic_get_data()->flags;
 
 		/* Panic data will be wiped by hard reset, so save it */
 		panic_get_reason(&reason, &info, &exception);
 		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_REASON, reason);
 		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_INFO, info);
 		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_EXCEPTION, exception);
+		hibdata_write(HIBDATA_INDEX_SAVED_PANIC_FLAGS, panic_flags);
 #endif
 
 		/*
diff --git a/chip/stm32/bkpdata.h b/chip/stm32/bkpdata.h
index 27715f8219..14bd3517cc 100644
--- a/chip/stm32/bkpdata.h
+++ b/chip/stm32/bkpdata.h
@@ -29,6 +29,13 @@ enum bkpdata_index {
 	BKPDATA_INDEX_PD1,		     /* USB-PD saved port1 state */
 	BKPDATA_INDEX_PD2,		     /* USB-PD saved port2 state */
 #endif
+#ifdef CONFIG_SOFTWARE_PANIC
+	/**
+	 * Saving the panic flags in case that AP thinks the panic is new
+	 * after a hard reset.
+	 */
+	BKPDATA_INDEX_SAVED_PANIC_FLAGS,     /* Saved panic flags */
+#endif
 	BKPDATA_COUNT
 };
 BUILD_ASSERT(STM32_BKP_ENTRIES >= BKPDATA_COUNT);
diff --git a/chip/stm32/system.c b/chip/stm32/system.c
index bba2f72fcc..0304c7b3be 100644
--- a/chip/stm32/system.c
+++ b/chip/stm32/system.c
@@ -249,7 +249,7 @@ void system_pre_init(void)
 {
 #ifdef CONFIG_SOFTWARE_PANIC
 	uint16_t reason, info;
-	uint8_t exception;
+	uint8_t exception, panic_flags;
 #endif
 
 	/* enable clock on Power module */
@@ -316,11 +316,14 @@ void system_pre_init(void)
 	reason = bkpdata_read(BKPDATA_INDEX_SAVED_PANIC_REASON);
 	info = bkpdata_read(BKPDATA_INDEX_SAVED_PANIC_INFO);
 	exception = bkpdata_read(BKPDATA_INDEX_SAVED_PANIC_EXCEPTION);
-	if (reason || info || exception) {
+	panic_flags = bkpdata_read(BKPDATA_INDEX_SAVED_PANIC_FLAGS);
+	if (reason || info || exception || panic_flags) {
 		panic_set_reason(reason, info, exception);
+		panic_get_data()->flags = panic_flags;
 		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_REASON, 0);
 		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_INFO, 0);
 		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_EXCEPTION, 0);
+		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_FLAGS, 0);
 	}
 #endif
 
@@ -367,6 +370,7 @@ void system_reset(int flags)
 #ifdef CONFIG_SOFTWARE_PANIC
 		uint32_t reason, info;
 		uint8_t exception;
+		uint8_t panic_flags = panic_get_data()->flags;
 
 		/* Panic data will be wiped by hard reset, so save it */
 		panic_get_reason(&reason, &info, &exception);
@@ -374,6 +378,7 @@ void system_reset(int flags)
 		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_REASON, reason);
 		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_INFO, info);
 		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_EXCEPTION, exception);
+		bkpdata_write(BKPDATA_INDEX_SAVED_PANIC_FLAGS, panic_flags);
 #endif
 
 #ifdef CHIP_FAMILY_STM32L