Check the header flags if an response is expected or not. If it is not
expected skip the receive part of ti_sci_do_xfer(). This prepares the
driver for one-way messages as prepare_sleep for Partial-IO.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
---
 drivers/firmware/ti_sci.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 555e41cc08080c78b3991a8d6c06f5030a576d72..9ef86ea27a3c9ac6b9aa4a838a4f5e9fc09a81a9 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -398,10 +398,13 @@ static void ti_sci_put_one_xfer(struct ti_sci_xfers_info *minfo,
 static inline int ti_sci_do_xfer(struct ti_sci_info *info,
 				 struct ti_sci_xfer *xfer)
 {
+	struct ti_sci_msg_hdr *hdr = (struct ti_sci_msg_hdr *)xfer->tx_message.buf;
 	int ret;
 	int timeout;
 	struct device *dev = info->dev;
 	bool done_state = true;
+	bool response_expected = !!(hdr->flags & (TI_SCI_FLAG_REQ_ACK_ON_PROCESSED |
+						  TI_SCI_FLAG_REQ_ACK_ON_RECEIVED));
 
 	ret = mbox_send_message(info->chan_tx, &xfer->tx_message);
 	if (ret < 0)
@@ -409,6 +412,9 @@ static inline int ti_sci_do_xfer(struct ti_sci_info *info,
 
 	ret = 0;
 
+	if (!response_expected)
+		goto no_response;
+
 	if (system_state <= SYSTEM_RUNNING) {
 		/* And we wait for the response. */
 		timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);
@@ -429,6 +435,7 @@ static inline int ti_sci_do_xfer(struct ti_sci_info *info,
 		dev_err(dev, "Mbox timedout in resp(caller: %pS)\n",
 			(void *)_RET_IP_);
 
+no_response:
 	/*
 	 * NOTE: we might prefer not to need the mailbox ticker to manage the
 	 * transfer queueing since the protocol layer queues things by itself.

-- 
2.45.2