[PATCH] thunderbolt: Keep Meteor Lake host routers powered in DP redrive mode

[PATCH] thunderbolt: Keep Meteor Lake host routers powered in DP redrive mode

[Hans van Essen via B4 Relay]

From: Hans van Essen <hans@kilurion.com>

When a DisplayPort Alt Mode (non-Thunderbolt) dock is connected to the
USB4 port of an Arrow Lake-H system with the integrated Meteor Lake-P
host router (8086:7ec2), the USB functions of the dock work but the DP
AUX transfers time out and no monitor is detected. It only works if the
port was used with a Thunderbolt dock before and the system was not
powered off in between; suspend and warm reboot keep it working.

The Barlow Ridge host routers already have QUIRK_KEEP_POWER_IN_DP_REDRIVE
so that the host router does not enter runtime suspend while the USB4
port is in DP redrive mode. Apply the same quirk to the integrated
Meteor Lake host routers. With this the driver logs "enter redrive mode,
keeping powered" when the dock is plugged in and the monitors come up
after a cold boot.

Tested on an ASUS ROG Zephyrus G16 (GU605CW) with a Lenovo ThinkPad
USB-C Dock (40AY).

Signed-off-by: Hans van Essen <hans@kilurion.com>
---
Single patch; adds the Meteor Lake (also used by Arrow Lake) integrated
host routers to the existing Barlow Ridge redrive runtime PM quirk.
---
 drivers/thunderbolt/quirks.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/thunderbolt/quirks.c b/drivers/thunderbolt/quirks.c
index 96b7fe0..770e6f9 100644
--- a/drivers/thunderbolt/quirks.c
+++ b/drivers/thunderbolt/quirks.c
@@ -103,13 +103,19 @@ static const struct tb_quirk tb_quirks[] = {
 	{ 0x8087, PCI_DEVICE_ID_INTEL_BARLOW_RIDGE_HUB_80G_BRIDGE, 0x01ea, 0x83b5,
 		  quirk_clx_disable },
 	/*
-	 * Block Runtime PM in DP redrive mode for Intel Barlow Ridge host
-	 * controllers.
+	 * Block Runtime PM in DP redrive mode for Intel Barlow Ridge and
+	 * Meteor Lake (also Arrow Lake) host controllers.
 	 */
 	{ 0x8087, PCI_DEVICE_ID_INTEL_BARLOW_RIDGE_HOST_80G_NHI, 0x0000, 0x0000,
 		  quirk_block_rpm_in_redrive },
 	{ 0x8087, PCI_DEVICE_ID_INTEL_BARLOW_RIDGE_HOST_40G_NHI, 0x0000, 0x0000,
 		  quirk_block_rpm_in_redrive },
+	{ 0x8087, PCI_DEVICE_ID_INTEL_MTL_M_NHI0, 0x0000, 0x0000,
+		  quirk_block_rpm_in_redrive },
+	{ 0x8087, PCI_DEVICE_ID_INTEL_MTL_P_NHI0, 0x0000, 0x0000,
+		  quirk_block_rpm_in_redrive },
+	{ 0x8087, PCI_DEVICE_ID_INTEL_MTL_P_NHI1, 0x0000, 0x0000,
+		  quirk_block_rpm_in_redrive },
 	/*
 	 * CLx is not supported on AMD USB4 Yellow Carp and Pink Sardine platforms.
 	 */

---
base-commit: 74957ec2a70c08fd3ddc5ca251aaf3c3a81c82d4
change-id: 20261006-tb-mtl-redrive-36be9e929945

Best regards,
--  
Hans van Essen <hans@kilurion.com>

Re: [PATCH] thunderbolt: Keep Meteor Lake host routers powered in DP redrive mode

[Mika Westerberg]

Hi,

On Tue, Oct 06, 2026 at 10:06:43AM +0200, Hans van Essen via B4 Relay wrote:
> From: Hans van Essen <hans@kilurion.com>
> 
> When a DisplayPort Alt Mode (non-Thunderbolt) dock is connected to the
> USB4 port of an Arrow Lake-H system with the integrated Meteor Lake-P
> host router (8086:7ec2), the USB functions of the dock work but the DP
> AUX transfers time out and no monitor is detected. It only works if the
> port was used with a Thunderbolt dock before and the system was not
> powered off in between; suspend and warm reboot keep it working.
> 
> The Barlow Ridge host routers already have QUIRK_KEEP_POWER_IN_DP_REDRIVE
> so that the host router does not enter runtime suspend while the USB4
> port is in DP redrive mode. Apply the same quirk to the integrated
> Meteor Lake host routers. With this the driver logs "enter redrive mode,
> keeping powered" when the dock is plugged in and the monitors come up
> after a cold boot.

Yes, Barlow Ridge needs it but it's a special case. ARL should not need
this - its all routed internally so something else is wrong here.

Can you share full dmesg when this issue happens? Please add
thunderbolt.dydnbg=+p too although this really has nothing to do with TB if
the port is in redrive mode.