feat(armv8-a/cpu): Handle unexpected powerdown behavior

We've observed that some platforms behave unexpectedly when performing power down. In these cases, after powerdown, the CPU cores are not awaken by interrupts as expected by Bao. This commit solve this, by adding the ability to skip the powerdown firmware call, instead relying on the fallback mechanism of using wfi. Signed-off-by: David Cerdeira <[email protected]>
bao-project · Oct 2, 2024 · 7b4d6f5 · 7b4d6f5
1 parent 02790d7
commit 7b4d6f5
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/src/arch/armv8/armv8-a/psci.c b/src/arch/armv8/armv8-a/psci.c
@@ -90,6 +90,13 @@ int32_t psci_standby()
 
 int32_t psci_power_down(enum wakeup_reason reason)
 {
+    /* We've observed that some platforms behave unexpectedly when performing
+     * power down. In these cases, after powerdown, the CPU cores are not awaken
+     * by interrupts as expected by Bao. */
+    if (!DEFINED(PLAT_PSCI_POWERDOWN_NOT_SUPPORTED)) {
+        return PSCI_E_NOT_SUPPORTED;
+    }
+
     extern void psci_boot_entry(unsigned long x0);
 
     uint32_t pwr_state_aux = PSCI_POWER_STATE_LVL_0 | PSCI_STATE_TYPE_POWERDOWN;