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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60512C433FE for ; Wed, 13 Oct 2021 14:06:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B0DC60E8B for ; Wed, 13 Oct 2021 14:06:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235592AbhJMOI1 (ORCPT ); Wed, 13 Oct 2021 10:08:27 -0400 Received: from netrider.rowland.org ([192.131.102.5]:54745 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S230347AbhJMOI0 (ORCPT ); Wed, 13 Oct 2021 10:08:26 -0400 Received: (qmail 893839 invoked by uid 1000); 13 Oct 2021 10:06:22 -0400 Date: Wed, 13 Oct 2021 10:06:22 -0400 From: Alan Stern To: Yinbo Zhu Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Patchwork Bot Subject: Re: [PATCH v6] usb: ohci: disable start-of-frame interrupt in ohci_rh_suspend Message-ID: <20211013140622.GA893308@rowland.harvard.edu> References: <1634095928-29639-1-git-send-email-zhuyinbo@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1634095928-29639-1-git-send-email-zhuyinbo@loongson.cn> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 13, 2021 at 11:32:08AM +0800, Yinbo Zhu wrote: > While going into S3 or S4 suspend, an OHCI host controller can > generate interrupt requests if the INTR_SF enable flag is set. The > interrupt handler routine isn't prepared for this and it doesn't turn > off the flag, causing an interrupt storm. > > To fix this problem, make ohci_rh_suspend() always disable INTR_SF > interrupts after processing the done list and the ED unlinks but > before the controller goes into the suspended (non-UsbOperational) > state. There's no reason to leave the flag enabled, since a > suspended controller doesn't generate Start-of-Frame packets. > > Signed-off-by: Yinbo Zhu > --- Acked-by: Alan Stern > Change in v6: > 1. Rework the commit log information. > 2. Move the key change code after ohci_work in > ohci_rh_suspend. > > > drivers/usb/host/ohci-hub.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c > index f474f2f..90cee19 100644 > --- a/drivers/usb/host/ohci-hub.c > +++ b/drivers/usb/host/ohci-hub.c > @@ -91,6 +91,9 @@ static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop) > update_done_list(ohci); > ohci_work(ohci); > > + /* All ED unlinks should be finished, no need for SOF interrupts */ > + ohci_writel(ohci, OHCI_INTR_SF, &ohci->regs->intrdisable); > + > /* > * Some controllers don't handle "global" suspend properly if > * there are unsuspended ports. For these controllers, put all > -- > 1.8.3.1 >