iwlwifi: pcie: make sure prph_info is set when treating wakeup IRQ

In some rare cases when the HW is in a bad state, we may get this interrupt when prph_info is not set yet. Then we will try to dereference it to check the sleep_notif element, which will cause an oops. Fix that by ignoring the interrupt if prph_info is not set yet. Signed-off-by: Luca Coelho <[email protected]> Link: https://lore.kernel.org/r/iwlwifi.20211219132536.0537aa562313.I183bb336345b9b3da196ba9e596a6f189fbcbd09@changeid Signed-off-by: Luca Coelho <[email protected]>
raspberrypi · Dec 21, 2021 · 459fc0f · 459fc0f
1 parent 73ca876
commit 459fc0f
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
@@ -2266,7 +2266,12 @@ irqreturn_t iwl_pcie_irq_msix_handler(int irq, void *dev_id)
 		}
 	}
 
-	if (inta_hw & MSIX_HW_INT_CAUSES_REG_WAKEUP) {
+	/*
+	 * In some rare cases when the HW is in a bad state, we may
+	 * get this interrupt too early, when prph_info is still NULL.
+	 * So make sure that it's not NULL to prevent crashing.
+	 */
+	if (inta_hw & MSIX_HW_INT_CAUSES_REG_WAKEUP && trans_pcie->prph_info) {
 		u32 sleep_notif =
 			le32_to_cpu(trans_pcie->prph_info->sleep_notif);
 		if (sleep_notif == IWL_D3_SLEEP_STATUS_SUSPEND ||