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 B138337AA6F for ; Mon, 23 Feb 2026 22:33:46 +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=1771886026; cv=none; b=Q1v0Q+VhLRS6CYXFSuseVQX3EA/CiFaFRYcsbzYXnViY06hel7xn//v7Bu0N8B14iZ3XWwR/4ifLMf3ED2Jpl7esHTdM8dI0boBmoH6Il+riZX5oUAX4FjdDVIT/AUwyzqXs/kfZu79hnnD3UtDmY9vd29S1sqBM/uHfKgTTnNY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771886026; c=relaxed/simple; bh=we3fL+ubwrqmXQwZNJrZ+tH8MqLuEGNfv2xLQgpsz2o=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=UFZnD4hVbPbfhM0JqUPMVo4E+pPig9mLPp0ZpOZkjqFa5i+0iZZRuw3TWKBaHXeZv1F0ImIEPRt91DPB7qINtGeN3Ntrd/JAqX3jOm19XRIthMOPEeYxzKr9WIpWJoNKM7hCCBOqTL4QDpla23wahoIanYDj9kA2hq568yjjJMw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=flB76zhJ; 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="flB76zhJ" Received: by smtp.kernel.org (Postfix) with ESMTPS id 5163DC19421 for ; Mon, 23 Feb 2026 22:33:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771886026; bh=we3fL+ubwrqmXQwZNJrZ+tH8MqLuEGNfv2xLQgpsz2o=; h=From:To:Subject:Date:In-Reply-To:References:From; b=flB76zhJv6u+Lzn30zcd1BEuoM4bkWJ5BJrbNWPzcHYXgB6gDE1NZ5Uw2NL/WkUnA wFLucfgAvkNvSygefwaq9uDAeAd3UU2t/znViCRHoQ0SPf1VquqjyAYqKuj2r5fTBo eWrxuY88QYORkAIVrNpN9Ez8HosY99fkyO3ZAZh/FrdHrlKC27WlkEhKrVLGELWpPt OCp72CLdXmOYrVzy1viCNRedxl6pzQLep6DGphq1BNr/60WEeGDyKmzXGVDex6r9uy 2RD48OLc1VPVb61X/AYVwymZVkOuNBSfJjqQYZuvgtR4hWOHfoBmxIOz+zxF/ZU/Ua 52vFLtgu5xzPw== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 3E683C433E1; Mon, 23 Feb 2026 22:33:46 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-usb@vger.kernel.org Subject: [Bug 221103] xhci_hcd: System lockup under CPU load during usbfs polling of USB devices on AMD platforms Date: Mon, 23 Feb 2026 22:33:46 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed 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: michal.pecio@gmail.com 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: Message-ID: In-Reply-To: References: 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=3D221103 --- Comment #18 from Micha=C5=82 Pecio (michal.pecio@gmail.com) --- My test got to almost 30k iterations with suspend-resume cycles, no crashes= . I loaded the CPUs with simple "while (1);" on each core. It seems the problem may be caused by a failure to resume the HC. The driver should handle it, but something goes wrong. I hoped it would be a stupid nu= ll pointer dereference and netconsole would give us stack trace, but no luck apparently. I tried crashing my system with SysRq-C and netconsole (over a = PCIe Ethernet NIC) delivered the panic message just fine, so not sure what happe= ns here. Could you enable dynamic debug and check if simply toggling power/control between 'on' and 'auto' produces the same xhci_suspend/xhci_resume messages? Would this be enough to hang the system, or is it necessary that somebody w= aits for the HC to resume to perform some operations on the root hub? Maybe it's just lack of necessary checks for dead HC somewhere. What's the state of power/control for those HCs which aren't causing proble= ms? Are they also getting resumed and suspended under your test, but without crashing? That would be at least one optimistic result in this whole mess :) There is another bug 221073 about some AMD HCs dying on resume from system sleep, may be related. So far nobody knows why it happens. --=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.=