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From:   Prashant Malani <pmalani@chromium.org>
To:     linux-kernel@vger.kernel.org
Cc:     Prashant Malani <pmalani@chromium.org>,
        Benson Leung <bleung@chromium.org>,
        Guenter Roeck <groeck@chromium.org>,
        chrome-platform@lists.linux.dev (open list:CHROMEOS EC USB TYPE-C
        DRIVER)
Subject: [PATCH v2 3/4] platform/chrome: cros_ec_typec: Configure muxes at start of port update
Date:   Tue,  8 Feb 2022 18:47:22 +0000
Message-Id: <20220208184721.1697194-4-pmalani@chromium.org>
In-Reply-To: <20220208184721.1697194-1-pmalani@chromium.org>
References: <20220208184721.1697194-1-pmalani@chromium.org>
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There are situations where the mux state reported by the Embedded
Controller (EC), might lag the partner "connected" state. So, the mux
state might still suggest that a partner is connected, while the PD
"connected" state, being in Try.SNK (for example) suggests that the
partner is disconnected.

In such a scenario, we will end up sending a disconnect command to the
mux driver, followed by a connect command, since the mux is configured
later. Avoid this by configuring the mux before
registering/disconnecting a partner.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---

Changes in v2:
- Change return at end of port_update() to just return 0.

 drivers/platform/chrome/cros_ec_typec.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 3d34ece7f790..3019e29f200d 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -965,6 +965,11 @@ static int cros_typec_port_update(struct cros_typec_data *typec, int port_num)
 	if (ret < 0)
 		return ret;
 
+	/* Update the switches if they exist, according to requested state */
+	ret = cros_typec_configure_mux(typec, port_num, &resp);
+	if (ret)
+		dev_warn(typec->dev, "Configure muxes failed, err = %d\n", ret);
+
 	dev_dbg(typec->dev, "Enabled %d: 0x%hhx\n", port_num, resp.enabled);
 	dev_dbg(typec->dev, "Role %d: 0x%hhx\n", port_num, resp.role);
 	dev_dbg(typec->dev, "Polarity %d: 0x%hhx\n", port_num, resp.polarity);
@@ -980,12 +985,7 @@ static int cros_typec_port_update(struct cros_typec_data *typec, int port_num)
 	if (typec->typec_cmd_supported)
 		cros_typec_handle_status(typec, port_num);
 
-	/* Update the switches if they exist, according to requested state */
-	ret = cros_typec_configure_mux(typec, port_num, &resp);
-	if (ret)
-		dev_warn(typec->dev, "Configure muxes failed, err = %d\n", ret);
-
-	return ret;
+	return 0;
 }
 
 static int cros_typec_get_cmd_version(struct cros_typec_data *typec)
-- 
2.35.0.263.gb82422642f-goog