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 E83A6C433F5 for ; Wed, 8 Dec 2021 21:45:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237486AbhLHVtJ (ORCPT ); Wed, 8 Dec 2021 16:49:09 -0500 Received: from netrider.rowland.org ([192.131.102.5]:45565 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S234434AbhLHVtI (ORCPT ); Wed, 8 Dec 2021 16:49:08 -0500 Received: (qmail 588242 invoked by uid 1000); 8 Dec 2021 16:45:35 -0500 Date: Wed, 8 Dec 2021 16:45:35 -0500 From: Alan Stern To: Kai-Heng Feng Cc: gregkh@linuxfoundation.org, mathias.nyman@linux.intel.com, Thinh Nguyen , Bixuan Cui , Andrew Lunn , Chris Chiu , Rajat Jain , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: hub: Resume hubs to find newly connected device Message-ID: References: <20211208070835.8877-1-kai.heng.feng@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211208070835.8877-1-kai.heng.feng@canonical.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Dec 08, 2021 at 03:08:33PM +0800, Kai-Heng Feng wrote: > When a new USB device gets plugged to nested hubs, the affected hub, > which connects to usb 2-1.4-port2, doesn't report there's any change, > hence the nested hubs go back to runtime suspend like nothing happened: That's a bug in the hub. When there's a change in the connection status of one of its ports, it should report this change to the kernel. > [ 281.032951] usb usb2: usb wakeup-resume > [ 281.032959] usb usb2: usb auto-resume > [ 281.032974] hub 2-0:1.0: hub_resume > [ 281.033011] usb usb2-port1: status 0263 change 0000 > [ 281.033077] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 281.049797] usb 2-1: usb wakeup-resume > [ 281.069800] usb 2-1: Waited 0ms for CONNECT > [ 281.069810] usb 2-1: finish resume > [ 281.070026] hub 2-1:1.0: hub_resume > [ 281.070250] usb 2-1-port4: status 0203 change 0000 > [ 281.070272] usb usb2-port1: resume, status 0 > [ 281.070282] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 > [ 281.089813] usb 2-1.4: usb wakeup-resume > [ 281.109792] usb 2-1.4: Waited 0ms for CONNECT > [ 281.109801] usb 2-1.4: finish resume > [ 281.109991] hub 2-1.4:1.0: hub_resume > [ 281.110147] usb 2-1.4-port2: status 0263 change 0000 > [ 281.110234] usb 2-1-port4: resume, status 0 > [ 281.110239] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s > [ 281.110266] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 281.110426] hub 2-1.4:1.0: hub_suspend > [ 281.110565] usb 2-1.4: usb auto-suspend, wakeup 1 > [ 281.130998] hub 2-1:1.0: hub_suspend > [ 281.137788] usb 2-1: usb auto-suspend, wakeup 1 > [ 281.142935] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 281.177828] usb 2-1: usb wakeup-resume > [ 281.197839] usb 2-1: Waited 0ms for CONNECT > [ 281.197850] usb 2-1: finish resume > [ 281.197984] hub 2-1:1.0: hub_resume > [ 281.198203] usb 2-1-port4: status 0203 change 0000 > [ 281.198228] usb usb2-port1: resume, status 0 > [ 281.198237] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 > [ 281.217835] usb 2-1.4: usb wakeup-resume > [ 281.237834] usb 2-1.4: Waited 0ms for CONNECT > [ 281.237845] usb 2-1.4: finish resume > [ 281.237990] hub 2-1.4:1.0: hub_resume > [ 281.238067] usb 2-1.4-port2: status 0263 change 0000 > [ 281.238148] usb 2-1-port4: resume, status 0 > [ 281.238152] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s > [ 281.238166] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 281.238385] hub 2-1.4:1.0: hub_suspend > [ 281.238523] usb 2-1.4: usb auto-suspend, wakeup 1 > [ 281.258076] hub 2-1:1.0: hub_suspend > [ 281.265744] usb 2-1: usb auto-suspend, wakeup 1 > [ 281.285976] hub 2-0:1.0: hub_suspend > [ 281.285988] usb usb2: bus auto-suspend, wakeup 1 > > So in addition to change event, wakes up the port if it's a hub to find > newly connected device: > [ 232.069881] usb usb2: usb wakeup-resume > [ 232.069889] usb usb2: usb auto-resume > [ 232.069904] hub 2-0:1.0: hub_resume > [ 232.069941] usb usb2-port1: status 0263 change 0000 > [ 232.069962] hub 2-1:1.0: state 8 ports 4 chg 0000 evt 0000 > [ 232.070034] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 232.112701] usb 2-1: Waited 0ms for CONNECT > [ 232.112711] usb 2-1: finish resume > [ 232.112900] hub 2-1:1.0: hub_resume > [ 232.113218] usb 2-1-port4: status 0203 change 0000 > [ 232.113267] hub 2-1.4:1.0: state 8 ports 4 chg 0000 evt 0000 > [ 232.152679] usb 2-1.4: Waited 0ms for CONNECT > [ 232.152691] usb 2-1.4: finish resume > [ 232.152829] hub 2-1.4:1.0: hub_resume > [ 232.153057] usb 2-1.4-port2: status 0263 change 0000 > [ 232.153094] hub 2-1.4.2:1.0: state 8 ports 3 chg 0000 evt 0000 > [ 232.153155] usb 2-1-port4: resume, status 0 > [ 232.153160] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s > [ 232.153192] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 232.153235] hub 2-1:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 232.153244] usb usb2-port1: resume, status 0 > [ 232.153274] usb 2-1.4.2: usb auto-resume > [ 232.153444] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 232.220690] usb 2-1.4.2: Waited 0ms for CONNECT > [ 232.220702] usb 2-1.4.2: finish resume > [ 232.220849] hub 2-1.4.2:1.0: hub_resume > [ 232.220870] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 > [ 232.220949] usb 2-1.4.2-port2: status 0203 change 0001 > [ 232.328747] usb 2-1.4.2-port2: status 0203, change 0000, 5.0 Gb/s > [ 232.408838] usb 2-1.4.2.2: new SuperSpeed USB device number 5 using xhci_hcd > [ 232.429734] usb 2-1.4.2.2: skipped 1 descriptor after endpoint > [ 232.429745] usb 2-1.4.2.2: skipped 1 descriptor after endpoint > [ 232.429827] usb 2-1.4.2.2: default language 0x0409 > [ 232.430192] usb 2-1.4.2.2: udev 5, busnum 2, minor = 132 > [ 232.430197] usb 2-1.4.2.2: New USB device found, idVendor=0781, idProduct=5581, bcdDevice= 1.00 > [ 232.430202] usb 2-1.4.2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > [ 232.430206] usb 2-1.4.2.2: Product: Ultra > [ 232.430209] usb 2-1.4.2.2: Manufacturer: SanDisk > [ 232.430212] usb 2-1.4.2.2: SerialNumber: 4C530001170905105491 > [ 232.430488] usb 2-1.4.2.2: usb_probe_device > [ 232.430493] usb 2-1.4.2.2: configuration #1 chosen from 1 choice > [ 232.431196] usb 2-1.4.2.2: Disabling U1 link state for device below second-tier hub. > [ 232.431199] usb 2-1.4.2.2: Plug device into first-tier hub to decrease power consumption. > [ 232.431469] usb 2-1.4.2.2: adding 2-1.4.2.2:1.0 (config #1, interface 0) > [ 232.431610] hub 2-1.4.2:1.0: state 7 ports 3 chg 0000 evt 0004 > > Signed-off-by: Kai-Heng Feng So because of this buggy hub, you now want to wake up _every_ hub in the system whenever any wakeup event occurs? Is this really a good idea? Is there a better way to solve the problem, such as a special quirk flag? Alan Stern > --- > drivers/usb/core/hub.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index 00070a8a65079..0c9442a8eab05 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -1227,6 +1227,10 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) > port_resumed)) > set_bit(port1, hub->change_bits); > > + if ((portstatus & USB_PORT_STAT_CONNECTION) && > + usb_hub_to_struct_hub(udev)) > + usb_kick_hub_wq(udev); > + > } else if (udev->persist_enabled) { > #ifdef CONFIG_PM > udev->reset_resume = 1; > -- > 2.32.0 >