From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751069AbdALM1E (ORCPT ); Thu, 12 Jan 2017 07:27:04 -0500 Received: from lelnx194.ext.ti.com ([198.47.27.80]:47397 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750755AbdALM1D (ORCPT ); Thu, 12 Jan 2017 07:27:03 -0500 Subject: Re: [PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd To: William Wu , References: <1484222606-15364-1-git-send-email-william.wu@rock-chips.com> CC: , , , , , , , , William wu From: Roger Quadros Message-ID: Date: Thu, 12 Jan 2017 14:26:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <1484222606-15364-1-git-send-email-william.wu@rock-chips.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org William, On 12/01/17 14:03, William Wu wrote: > From: William wu > > On some platforms(e.g. rk3399 board), we can call hcd_add/remove > consecutively without calling usb_put_hcd/usb_create_hcd in between, > so hcd->flags can be stale. > > If the HC dies due to whatever reason then without this patch we get > the below error on next hcd_add. > > [173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up > [173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller > [173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6 > [173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM. > [173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003 > [173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1 > [173.297222] usb usb6: Product: xHCI Host Controller > [173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd > [173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto > [173.298680] hub 6-0:1.0: USB hub found > [173.298749] hub 6-0:1.0: 1 port detected > [173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected > [173.395418] hub 5-0:1.0: activate --> -19 > [173.603447] irq 228: nobody cared (try booting with the "irqpoll" option) > [173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9 > [173.603513] Hardware name: Google Kevin (DT) > [173.603531] Call trace: > [173.603568] [] dump_backtrace+0x0/0x160 > [173.603596] [] show_stack+0x20/0x28 > [173.603623] [] dump_stack+0x90/0xb0 > [173.603650] [] __report_bad_irq+0x48/0xe8 > [173.603674] [] note_interrupt+0x1e8/0x28c > [173.603698] [] handle_irq_event_percpu+0x1d4/0x25c > [173.603722] [] handle_irq_event+0x4c/0x7c > [173.603748] [] handle_fasteoi_irq+0xb4/0x124 > [173.603777] [] generic_handle_irq+0x30/0x44 > [173.603804] [] __handle_domain_irq+0x90/0xbc > [173.603827] [] gic_handle_irq+0xcc/0x188 > ... > [173.604500] [] el1_irq+0x80/0xf8 > [173.604530] [] cpu_startup_entry+0x38/0x3cc > [173.604558] [] rest_init+0x8c/0x94 > [173.604585] [] start_kernel+0x3d0/0x3fc > [173.604607] [<0000000000b16000>] 0xb16000 > [173.604622] handlers: > [173.604648] [] usb_hcd_irq > [173.604673] Disabling IRQ #228 > > Signed-off-by: William wu > Signed-off-by: William wu > --- > drivers/usb/core/hcd.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c > index 479e223..612fab6 100644 > --- a/drivers/usb/core/hcd.c > +++ b/drivers/usb/core/hcd.c > @@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd) > } > > usb_put_invalidate_rhdev(hcd); > + hcd->flags = 0; > } > EXPORT_SYMBOL_GPL(usb_remove_hcd); > > I suggest to initialize hcd->flags to 0 in usb_add_hcd() instead. cheers, -roger