* [PATCH v2] usb: typec: thunderbolt: Set enter_vdo during initialization
@ 2026-03-24 10:30 Andrei Kuchynski
2026-03-27 17:55 ` Benson Leung
0 siblings, 1 reply; 2+ messages in thread
From: Andrei Kuchynski @ 2026-03-24 10:30 UTC (permalink / raw)
To: Heikki Krogerus, linux-usb, linux-kernel
Cc: Greg Kroah-Hartman, Andrei Kuchynski, stable, Madhu M
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().
Cc: stable@vger.kernel.org
Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode")
Tested-by: Madhu M <madhu.m@intel.corp-partner.google.com>
Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
Changes in V2:
- Marked as a Fix
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
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH v2] usb: typec: thunderbolt: Set enter_vdo during initialization
2026-03-24 10:30 [PATCH v2] usb: typec: thunderbolt: Set enter_vdo during initialization Andrei Kuchynski
@ 2026-03-27 17:55 ` Benson Leung
0 siblings, 0 replies; 2+ messages in thread
From: Benson Leung @ 2026-03-27 17:55 UTC (permalink / raw)
To: Andrei Kuchynski
Cc: Heikki Krogerus, linux-usb, linux-kernel, Greg Kroah-Hartman,
stable, Madhu M
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On Tue, Mar 24, 2026 at 10:30:12AM +0000, Andrei Kuchynski wrote:
> 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().
>
> Cc: stable@vger.kernel.org
> Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode")
> Tested-by: Madhu M <madhu.m@intel.corp-partner.google.com>
> Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
> ---
> Changes in V2:
> - Marked as a Fix
>
> 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
>
>
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