From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CCD4C433EF for ; Sat, 1 Jan 2022 01:49:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231846AbiAABtr (ORCPT ); Fri, 31 Dec 2021 20:49:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231722AbiAABtq (ORCPT ); Fri, 31 Dec 2021 20:49:46 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 699EDC061574 for ; Fri, 31 Dec 2021 17:49:46 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A4BB5B81D57 for ; Sat, 1 Jan 2022 01:49:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPS id 2FFE7C36AED for ; Sat, 1 Jan 2022 01:49:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641001783; bh=WNThEOjIQkYC/YTmtmXVnU94D2GQf646bcS8fshobxo=; h=From:To:Subject:Date:In-Reply-To:References:From; b=gYEdsH9Fics9Q5I/DSb2Bmvw/MyNSyv1WIlFi4fyC15p0sDd43F8//rwED0Q9hQHf ILp6uq1lxigah3LH9ZbS1ZuaBy/Vno86Cm/YCa0FsCcAOqAMfcdH1cl3jOLRI076EO Kg9G2eVLCzjcV+F10vejXZXuWh6H93/MPlusv0f1mXCYKzUzHKgCSa6IwggTv9OtCG oQYvJY+5iNteQmQ62EptSvPA+0m8+Gy2cDxwAHRt6Wx1IENenusF6NH5ha7+0Kmr29 uPYRZrkWkyyv0zo+seTwz26aAgQvBgeaYNbJKOBb64zUaxy62SbcHdrnNLhfOYeS8M eDu/7x0t/wi4w== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 0B19CC05FC8; Sat, 1 Jan 2022 01:49:43 +0000 (UTC) From: bugzilla-daemon@bugzilla.kernel.org To: linux-usb@vger.kernel.org Subject: [Bug 213839] XHCI 7 port usb hub does not work correctly Date: Sat, 01 Jan 2022 01:49:42 +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: stern@rowland.harvard.edu X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 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 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=3D213839 --- Comment #10 from Alan Stern (stern@rowland.harvard.edu) --- So far I have only looked at the Linux trace. It shows two unusual things I don't understand. One is that some process (I don't know which) re-reads the hub's device and configuration descriptors while the second device is being initialized, and apparently as a result of this the process decides to reset the hub. Why d= oes this happen? The second is that when the descriptors are re-read, the hub's config descriptor has changed! The original bmAttributes value is 0xe0, as shown = in the lsusb output above. But the bmAttributes value in the trace is 0xc0; t= he changed bit is the flag for Wakeup support. Most likely this is a bug in t= he hub's firmware. Perhaps additional debugging information will help. You can enable dynamic debugging and snooping for USB by doing: echo 'module usbcore =3Dp' >/sys/kernel/debug/dynamic_debug/control echo 1 >/sys/module/usbcore/parameters/usbfs_snoop Clear the kernel log buffer by doing: dmesg -C Then plug in the hub and and plug in a device to one of the non-working por= ts.=20 Let's see what the dmesg log shows after that. Another unusual thing shows up clearly in the trace: The autosuspend_delay_= ms time is set to a very low value; it looks like 20 ms. You might get better results leaving the delay set to its default value of 2 seconds. Or turn U= SB autosuspend off entirely by doing: echo -1 >/sys/module/usbcore/parameters/autosuspend before plugging in the hub. --=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.=