From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C1C7348895 for ; Sat, 28 Mar 2026 22:26:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774736801; cv=none; b=h6R4tvHCg15UFsFccEHfnWJ9WcnalMHXU7SSX/ct1DsBnO2kpyih/+K4NCF/w2m9IMT2MNWDNYZOj2EbZGoecm/tQWhECs1mA12x69bJiVGu7UnUrkA8vN2Vo/UrH8uQWypScU7XvRSFganTcA4qC2dIYPD0iDpD2DEqqPW1EsI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774736801; c=relaxed/simple; bh=xnyPq9fTT0/hHGzhee8t035BVxPGc6W8YgcnaKYfBB4=; h=From:To:Subject:Date:Message-ID:Content-Type:MIME-Version; b=KPTJTUMdXJJTQ8qxaYjNtT2GTmkiqf8tc02T72WqMNLKCqJTgDOCxNifT+X2aodX85lTebCbNOylmhSMMk3/NvzoZSI1Tx1BHJR7rknZb8eoS50qs5h8wmoSn2lYWhwLaQor7JA2n32yCSQdj9L2USkC4PhQHxSNCdKBrjvR9kI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GqZ58gAc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GqZ58gAc" Received: by smtp.kernel.org (Postfix) with ESMTPS id D6A3EC4CEF7 for ; Sat, 28 Mar 2026 22:26:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774736800; bh=xnyPq9fTT0/hHGzhee8t035BVxPGc6W8YgcnaKYfBB4=; h=From:To:Subject:Date:From; b=GqZ58gAcZTvSAt2b8WEnTXz8ZiR1W2ZctpJPEdOczOR2xS6Nx1J3x5z1ojO2xvBby T93MZ9ynjzX56GYATG6Al4PZh+YMh+8U+5PwzT640iAGu9qP8cMRwnoVBUOeum/g43 alKdZCgyrj3wr16fOlhZw1dKJZzZstZA2rLngpYz2BFi4DFWX6g0pENJ8jeR5XXRBU 8WqVeo2mG+952KxDbmEGn0aAfsIMvNdyigNUr7WcINHLrW5qip0TPkA4uF6Ab6XJXR axUCMj16nHcDD/9Era4pdvjYdxQu6PDZyHID5EQzQZNsReQjTygtIh6hM6tpQKK3Lx 1NiO1dWH4Ytjg== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id C2C0CC433E1; Sat, 28 Mar 2026 22:26:40 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-usb@vger.kernel.org Subject: [Bug 221293] New: Thunderbolt: "failed to calculate available bandwidth" causes DisplayPort tunnel drop with Apple Studio Display Date: Sat, 28 Mar 2026 22:26:40 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: AssignedTo drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: USB X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: aylin.ahmed@jetbot.co.uk X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter cf_regression attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D221293 Bug ID: 221293 Summary: Thunderbolt: "failed to calculate available bandwidth" causes DisplayPort tunnel drop with Apple Studio Display Product: Drivers Version: 2.5 Hardware: All OS: Linux Status: NEW Severity: normal Priority: P3 Component: USB Assignee: drivers_usb@kernel-bugs.kernel.org Reporter: aylin.ahmed@jetbot.co.uk Regression: No Created attachment 309779 --> https://bugzilla.kernel.org/attachment.cgi?id=3D309779&action=3Dedit dmesg thunderbolt log and hardware details Apple Studio Display connected via Thunderbolt to ThinkPad X1 Carbon intermittently loses DisplayPort tunnel. The kernel logs: thunderbolt 0000:00:0d.3: 0:12 <-> 1:20 (USB3): failed to calculate avail= able bandwidth followed by "failed to reach state TB_PORT_UP" and device disconnect. USB3 hub (05ac:8014) and DP contend for bandwidth. Manually unbinding the U= SB3 hub restores DP, confirming contention. Suspend/resume recovers correctly b= ut DPMS wake does not. Hardware: ThinkPad X1 Carbon, Intel Gen12 TB controller, kernel 6.8.0-106-generic, Ubuntu 24.x Wayland. Full dmesg and hardware details attached. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=