From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751069AbdAMChv (ORCPT ); Thu, 12 Jan 2017 21:37:51 -0500 Received: from regular1.263xmail.com ([211.150.99.134]:35358 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877AbdAMCht (ORCPT ); Thu, 12 Jan 2017 21:37:49 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: wulf@rock-chips.com X-FST-TO: groeck@google.com X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: wulf@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd To: Roger Quadros , Alan Stern References: Cc: William Wu , gregkh@linuxfoundation.org, heiko@sntech.de, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-rockchip@lists.infradead.org, frank.wang@rock-chips.com, huangtao@rock-chips.com, dianders@google.com, groeck@google.com From: wlf Message-ID: <1289c17d-baed-053d-50e1-91c57bf04583@rock-chips.com> Date: Fri, 13 Jan 2017 10:37:18 +0800 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: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Roger， 在 2017年01月12日 23:38, Roger Quadros 写道: > On 12/01/17 17:33, Alan Stern wrote: >> On Thu, 12 Jan 2017, Roger Quadros wrote: >> >>> 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 >> Roger, didn't you originally propose this very same patch in >> >> http://marc.info/?l=linux-usb&m=146556415503583&w=2 >> >> (and of course, the earlier versions before v10)? What happened to it? > Alan, You are right. That patch got lost in the ML. Looks like I didn't push it hard enough > and then forgot about it. Sorry. > > William, > > You don't need to do any changes. My earlier version was clearing the flag > in usb_add_hcd() and I guess Alan suggested to move it to usb_remove_hcd(). > > So your patch is good. > You can add my. > > Acked-by: Roger Quadros > > cheers, > -roger Thanks very much for your suggestion，I will add acked-by immediately. > > >