[PATCH] usb: typec: thunderbolt: Set enter_vdo during initialization
From: Andrei Kuchynski
Date: Tue Mar 24 2026 - 05:10:41 EST
In the current implementation, if a cable's alternate mode enter operation
is not supported, the tbt->plug[TYPEC_PLUG_SOP_P] pointer is cleared by the
time tbt_enter_mode() is called. This prevents the driver from identifying
the cable's VDO.
As a result, the Thunderbolt connection falls back to the default
TBT_CABLE_USB3_PASSIVE speed, even if the cable supports higher speeds.
To ensure the correct VDO value is used during mode entry, calculate and
store the enter_vdo earlier during the initialization phase in tbt_ready().
Tested-by: Madhu M <madhu.m@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrei Kuchynski <akuchynski@xxxxxxxxxxxx>
---
drivers/usb/typec/altmodes/thunderbolt.c | 44 ++++++++++++------------
1 file changed, 22 insertions(+), 22 deletions(-)
diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
index c4c5da6154da9..32250b94262a9 100644
--- a/drivers/usb/typec/altmodes/thunderbolt.c
+++ b/drivers/usb/typec/altmodes/thunderbolt.c
@@ -39,28 +39,7 @@ static bool tbt_ready(struct typec_altmode *alt);
static int tbt_enter_mode(struct tbt_altmode *tbt)
{
- struct typec_altmode *plug = tbt->plug[TYPEC_PLUG_SOP_P];
- u32 vdo;
-
- vdo = tbt->alt->vdo & (TBT_VENDOR_SPECIFIC_B0 | TBT_VENDOR_SPECIFIC_B1);
- vdo |= tbt->alt->vdo & TBT_INTEL_SPECIFIC_B0;
- vdo |= TBT_MODE;
-
- if (plug) {
- if (typec_cable_is_active(tbt->cable))
- vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
-
- vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_SPEED(plug->vdo));
- vdo |= plug->vdo & TBT_CABLE_ROUNDED;
- vdo |= plug->vdo & TBT_CABLE_OPTICAL;
- vdo |= plug->vdo & TBT_CABLE_RETIMER;
- vdo |= plug->vdo & TBT_CABLE_LINK_TRAINING;
- } else {
- vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_USB3_PASSIVE);
- }
-
- tbt->enter_vdo = vdo;
- return typec_altmode_enter(tbt->alt, &vdo);
+ return typec_altmode_enter(tbt->alt, &tbt->enter_vdo);
}
static void tbt_altmode_work(struct work_struct *work)
@@ -337,6 +316,7 @@ static bool tbt_ready(struct typec_altmode *alt)
{
struct tbt_altmode *tbt = typec_altmode_get_drvdata(alt);
struct typec_altmode *plug;
+ u32 vdo;
if (tbt->cable)
return true;
@@ -364,6 +344,26 @@ static bool tbt_ready(struct typec_altmode *alt)
tbt->plug[i] = plug;
}
+ vdo = tbt->alt->vdo & (TBT_VENDOR_SPECIFIC_B0 | TBT_VENDOR_SPECIFIC_B1);
+ vdo |= tbt->alt->vdo & TBT_INTEL_SPECIFIC_B0;
+ vdo |= TBT_MODE;
+ plug = tbt->plug[TYPEC_PLUG_SOP_P];
+
+ if (plug) {
+ if (typec_cable_is_active(tbt->cable))
+ vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;
+
+ vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_SPEED(plug->vdo));
+ vdo |= plug->vdo & TBT_CABLE_ROUNDED;
+ vdo |= plug->vdo & TBT_CABLE_OPTICAL;
+ vdo |= plug->vdo & TBT_CABLE_RETIMER;
+ vdo |= plug->vdo & TBT_CABLE_LINK_TRAINING;
+ } else {
+ vdo |= TBT_ENTER_MODE_CABLE_SPEED(TBT_CABLE_USB3_PASSIVE);
+ }
+
+ tbt->enter_vdo = vdo;
+
return true;
}
--
2.53.0.983.g0bb29b3bc5-goog