drivers: serial: stm32: prevent suspend to ram when operation in progress

gautierg-st · carlescufi · commit be26c71fd40e · 2024-01-25T08:55:02.000+01:00
Prevent the system to enter Suspend to RAM state while UART operation is
in progress.

Signed-off-by: Guillaume Gautier &lt;guillaume.gautier-ext@st.com&gt;
diff --git a/drivers/serial/uart_stm32.c b/drivers/serial/uart_stm32.c
@@ -96,6 +96,9 @@ static void uart_stm32_pm_policy_state_lock_get(const struct device *dev)
 	if (!data->pm_policy_state_on) {
 		data->pm_policy_state_on = true;
 		pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
+		if (IS_ENABLED(CONFIG_PM_S2RAM)) {
+			pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_RAM, PM_ALL_SUBSTATES);
+		}
 	}
 }
 
@@ -106,6 +109,9 @@ static void uart_stm32_pm_policy_state_lock_put(const struct device *dev)
 	if (data->pm_policy_state_on) {
 		data->pm_policy_state_on = false;
 		pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);
+		if (IS_ENABLED(CONFIG_PM_S2RAM)) {
+			pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_RAM, PM_ALL_SUBSTATES);
+		}
 	}
 }
 #endif /* CONFIG_PM */

Original file line number	Diff line number	Diff line change
`@@ -96,6 +96,9 @@ static void uart_stm32_pm_policy_state_lock_get(const struct device *dev)`
`96`	`96`	`if (!data->pm_policy_state_on) {`
`97`	`97`	`data->pm_policy_state_on = true;`
`98`	`98`	`pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);`
	`99`	`+ if (IS_ENABLED(CONFIG_PM_S2RAM)) {`
	`100`	`+ pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_RAM, PM_ALL_SUBSTATES);`
	`101`	`+ }`
`99`	`102`	`}`
`100`	`103`	`}`
`101`	`104`
`@@ -106,6 +109,9 @@ static void uart_stm32_pm_policy_state_lock_put(const struct device *dev)`
`106`	`109`	`if (data->pm_policy_state_on) {`
`107`	`110`	`data->pm_policy_state_on = false;`
`108`	`111`	`pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_IDLE, PM_ALL_SUBSTATES);`
	`112`	`+ if (IS_ENABLED(CONFIG_PM_S2RAM)) {`
	`113`	`+ pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_RAM, PM_ALL_SUBSTATES);`
	`114`	`+ }`
`109`	`115`	`}`
`110`	`116`	`}`
`111`	`117`	`#endif /* CONFIG_PM */`