[PATCH v4 2/3] usb: typec: ucsi: Add duplicate detection to nvidia registration path

Chia-Lin Kao (AceLan)
2026-04-13T07:36:13Z

Extend the duplicate altmode detection to ucsi_register_altmodes_nvidia()
which is used when a driver provides the update_altmodes() callback.

This ensures all drivers benefit from duplicate detection, whether they
use the standard registration path or the nvidia path with update_altmodes
callback.

Without this fix, drivers using the nvidia path (like yoga_c630) would
still encounter duplicate altmode registration errors from buggy firmware.

Fixes: a79f16efcd00 ("usb: typec: ucsi: Add support for the partner USB Modes")
Cc: stable@vger.kernel.org
Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
--
v4. rebase
---
drivers/usb/typec/ucsi/ucsi.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index eebbb80fae566..43389fc7e13f2 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -619,19 +619,25 @@ ucsi_register_altmodes_nvidia(struct ucsi_connector *con, u8 recipient)

/* now register altmodes */
for (i = 0; i < max_altmodes; i++) {
- memset(&desc, 0, sizeof(desc));
- if (multi_dp) {
- desc.svid = updated[i].svid;
- desc.vdo = updated[i].mid;
- } else {
- desc.svid = orig[i].svid;
- desc.vdo = orig[i].mid;
- }
- desc.roles = TYPEC_PORT_DRD;
+ struct ucsi_altmode *altmode_array = multi_dp ? updated : orig;

- if (!desc.svid)
+ if (!altmode_array[i].svid)
return 0;

+ /*
+ * Check for duplicates in current array and already
+ * registered altmodes. Skip if duplicate found.
+ */
+ if (ucsi_altmode_is_duplicate(con, recipient, altmode_array, i,
+ altmode_array[i].svid,
+ altmode_array[i].mid, i))
+ continue;
+
+ memset(&desc, 0, sizeof(desc));
+ desc.svid = altmode_array[i].svid;
+ desc.vdo = altmode_array[i].mid;
+ desc.roles = TYPEC_PORT_DRD;
+
ret = ucsi_register_altmode(con, &desc, recipient);
if (ret)
return ret;
--
2.53.0