remoteproc/mediatek: acknowledge watchdog IRQ after handled

Acknowledges watchdog IRQ after handled or kernel keeps receiving the
interrupt.

Fixes: fd0b6c1f ("remoteproc/mediatek: Add support for mt8192 SCP")
Signed-off-by: NTzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20210127082046.3735157-1-tzungbi@google.comSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/mtk_common.h

@@ -47,6 +47,7 @@
 
 #define MT8192_CORE0_SW_RSTN_CLR	0x10000
 #define MT8192_CORE0_SW_RSTN_SET	0x10004
+#define MT8192_CORE0_WDT_IRQ		0x10030
 #define MT8192_CORE0_WDT_CFG		0x10034
 
 #define SCP_FW_VER_LEN			32

drivers/remoteproc/mtk_scp.c

@@ -197,17 +197,19 @@ static void mt8192_scp_irq_handler(struct mtk_scp *scp)
 
 	scp_to_host = readl(scp->reg_base + MT8192_SCP2APMCU_IPC_SET);
 
-	if (scp_to_host & MT8192_SCP_IPC_INT_BIT)
+	if (scp_to_host & MT8192_SCP_IPC_INT_BIT) {
 		scp_ipi_handler(scp);
-	else
-		scp_wdt_handler(scp, scp_to_host);
 
-	/*
-	 * SCP won't send another interrupt until we clear
-	 * MT8192_SCP2APMCU_IPC.
-	 */
-	writel(MT8192_SCP_IPC_INT_BIT,
-	       scp->reg_base + MT8192_SCP2APMCU_IPC_CLR);
+		/*
+		 * SCP won't send another interrupt until we clear
+		 * MT8192_SCP2APMCU_IPC.
+		 */
+		writel(MT8192_SCP_IPC_INT_BIT,
+		       scp->reg_base + MT8192_SCP2APMCU_IPC_CLR);
+	} else {
+		scp_wdt_handler(scp, scp_to_host);
+		writel(1, scp->reg_base + MT8192_CORE0_WDT_IRQ);
+	}
 }
 
 static irqreturn_t scp_irq_handler(int irq, void *priv)