[PATCH v2] usb: typec: tcpci: pass correct rx_type to tcpm_pd_receive()

From: Xu Yang <[email protected]>

Previously, tcpci_irq() always passed TCPC_TX_SOP as the receive type
to tcpm_pd_receive(), ignoring the actual frame type reported by the
TCPC_RX_BUF_FRAME_TYPE register.

Cache the TCPC_RX_DETECT register value in rx_type_mask variable. When
a PD messageis received, read TCPC_RX_BUF_FRAME_TYPE register and handle
the message only if its frame type is enabled in mask.

The TCPC_RX_BUF_FRAME_TYPE register records the received message type,
which has a 1:1 mapping to enum tcpm_transmit_type.

Fixes: fb7ff25ae433 ("usb: typec: tcpm: add discover identity support for SOP'")
Cc: [email protected]
Signed-off-by: Xu Yang <[email protected]>

---
Changes in v2:
 - add fix tag
 - check return value when get RX SOP type
 - pass all possible RX message type to tcpm_pd_receive()
 - cache TCPC_RX_DETECT to filter out unallowed RX messages as suggested by Badhri
---
 drivers/usb/typec/tcpm/tcpci.c | 12 +++++++++++-
 include/linux/usb/tcpci.h      |  1 +
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index 7ac7000b2d13..6717ac914c6a 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -38,6 +38,7 @@ struct tcpci {
 
 	struct regmap *regmap;
 	unsigned int alert_mask;
+	unsigned int rx_type_mask;
 
 	bool controls_vbus;
 
@@ -488,6 +489,8 @@ static int tcpci_set_pd_rx(struct tcpc_dev *tcpc, bool enable)
 		if (tcpci->data->cable_comm_capable)
 			reg |= TCPC_RX_DETECT_SOP1;
 	}
+
+	tcpci->rx_type_mask = reg;
 	ret = regmap_write(tcpci->regmap, TCPC_RX_DETECT, reg);
 	if (ret < 0)
 		return ret;
@@ -749,6 +752,7 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
 	if (status & TCPC_ALERT_RX_STATUS) {
 		struct pd_message msg;
 		unsigned int cnt, payload_cnt;
+		enum tcpm_transmit_type rx_type;
 		u16 header;
 
 		regmap_read(tcpci->regmap, TCPC_RX_BYTE_CNT, &cnt);
@@ -773,10 +777,16 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
 			regmap_raw_read(tcpci->regmap, TCPC_RX_DATA,
 					&msg.payload, payload_cnt);
 
+		ret = regmap_read(tcpci->regmap, TCPC_RX_BUF_FRAME_TYPE, &rx_type);
+		if (ret)
+			return ret;
+
 		/* Read complete, clear RX status alert bit */
 		tcpci_write16(tcpci, TCPC_ALERT, TCPC_ALERT_RX_STATUS);
 
-		tcpm_pd_receive(tcpci->port, &msg, TCPC_TX_SOP);
+		rx_type &= TCPC_RX_BUF_FRAME_TYPE_MASK;
+		if (tcpci->rx_type_mask & BIT(rx_type))
+			tcpm_pd_receive(tcpci->port, &msg, rx_type);
 	}
 
 	if (tcpci->data->vbus_vsafe0v && (status & TCPC_ALERT_EXTENDED_STATUS)) {
diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
index f7f5cfbdef12..9b46a6bc762c 100644
--- a/include/linux/usb/tcpci.h
+++ b/include/linux/usb/tcpci.h
@@ -144,6 +144,7 @@
 #define TCPC_RX_BUF_FRAME_TYPE		0x31
 #define TCPC_RX_BUF_FRAME_TYPE_SOP	0
 #define TCPC_RX_BUF_FRAME_TYPE_SOP1	1
+#define TCPC_RX_BUF_FRAME_TYPE_MASK	GENMASK(2, 0)
 #define TCPC_RX_HDR			0x32
 #define TCPC_RX_DATA			0x34 /* through 0x4f */
 
-- 
2.34.1