linux-kernel - [PATCH 3/8] usb: typec: ucsi: yoga-c630: remove duplicate AltModes

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Message-Id: <20250621-c630-ucsi-v1-3-a86de5e11361@oss.qualcomm.com>
Date: Sat, 21 Jun 2025 21:12:58 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Bryan O'Donoghue <bryan.odonoghue@...aro.org>,
        Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>
Cc: linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org
Subject: [PATCH 3/8] usb: typec: ucsi: yoga-c630: remove duplicate AltModes

On Lenovo Yoga C630 the EC firmware is buggy and it returns duplicate
AltModes over and over again instead of returning an empty one, as
demanded by the spec. Ignore extra altmodes by zeroing them in the
update_altmodes() callback. It is not possible to shortcut that in the
sync_control() callback since we need to know if the AltMode matches the
first reported AltMode or not.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
---
 drivers/usb/typec/ucsi/ucsi_yoga_c630.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi_yoga_c630.c b/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
index 47e8dd5b255b2b306dd9c3d6ac8c3b896954981a..7cc1342d6e2f1d2c6f5b95caa48a711a280b91d3 100644
--- a/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
+++ b/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
@@ -71,6 +71,28 @@ static int yoga_c630_ucsi_async_control(struct ucsi *ucsi, u64 command)
 	return yoga_c630_ec_ucsi_write(uec->ec, (u8*)&command);
 }
 
+static bool yoga_c630_ucsi_update_altmodes(struct ucsi *ucsi,
+					   u8 recipient,
+					   struct ucsi_altmode *orig,
+					   struct ucsi_altmode *updated)
+{
+	int i;
+
+	if (orig[0].svid == 0 || recipient != UCSI_RECIPIENT_SOP)
+		return false;
+
+	/* EC is nice and repeats altmodes again and again. Ignore copies. */
+	for (i = 1; i < UCSI_MAX_ALTMODES; i++) {
+		if (orig[i].svid == orig[0].svid) {
+			dev_dbg(ucsi->dev, "Found duplicate altmodes, starting from %d\n", i);
+			memset(&orig[i], 0, (UCSI_MAX_ALTMODES - i) * sizeof(*orig));
+			break;
+		}
+	}
+
+	return false;
+}
+
 static const struct ucsi_operations yoga_c630_ucsi_ops = {
 	.read_version = yoga_c630_ucsi_read_version,
 	.read_cci = yoga_c630_ucsi_read_cci,
@@ -78,6 +100,7 @@ static const struct ucsi_operations yoga_c630_ucsi_ops = {
 	.read_message_in = yoga_c630_ucsi_read_message_in,
 	.sync_control = ucsi_sync_control_common,
 	.async_control = yoga_c630_ucsi_async_control,
+	.update_altmodes = yoga_c630_ucsi_update_altmodes,
 };
 
 static int yoga_c630_ucsi_notify(struct notifier_block *nb,

-- 
2.39.5