From: Madhusudanarao Amara <madhusudanarao.amara@intel.com>
Date: Wed, 16 Sep 2020 12:11:02 +0300
Subject: usb: typec: intel_pmc_mux: Handle SCU IPC error conditions
Git-commit: d69030c91b3765934048151792f141f0571efa86
Patch-mainline: v5.9-rc6
References: git-fixes

Check and return if there are errors. The response bits are valid
only on no errors.

Fixes: b7404a29cd3d ("usb: typec: intel_pmc_mux: Definitions for response status bits")
Signed-off-by: Madhusudanarao Amara <madhusudanarao.amara@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200916091102.27118-4-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 drivers/usb/typec/mux/intel_pmc_mux.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c
index ec7da0fa3cf8..676b525c2a66 100644
--- a/drivers/usb/typec/mux/intel_pmc_mux.c
+++ b/drivers/usb/typec/mux/intel_pmc_mux.c
@@ -125,13 +125,19 @@ static int hsl_orientation(struct pmc_usb_port *port)
 static int pmc_usb_command(struct pmc_usb_port *port, u8 *msg, u32 len)
 {
 	u8 response[4];
+	int ret;
 
 	/*
 	 * Error bit will always be 0 with the USBC command.
-	 * Status can be checked from the response message.
+	 * Status can be checked from the response message if the
+	 * function intel_scu_ipc_dev_command succeeds.
 	 */
-	intel_scu_ipc_dev_command(port->pmc->ipc, PMC_USBC_CMD, 0, msg, len,
-				  response, sizeof(response));
+	ret = intel_scu_ipc_dev_command(port->pmc->ipc, PMC_USBC_CMD, 0, msg,
+					len, response, sizeof(response));
+
+	if (ret)
+		return ret;
+
 	if (response[2] & PMC_USB_RESP_STATUS_FAILURE) {
 		if (response[2] & PMC_USB_RESP_STATUS_FATAL)
 			return -EIO;