From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org ([198.145.29.96]:47592 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751230AbeDQOca (ORCPT ); Tue, 17 Apr 2018 10:32:30 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Tue, 17 Apr 2018 22:32:28 +0800 From: leiwan@codeaurora.org To: Greg KH Cc: stable@vger.kernel.org Subject: Re: refine xhci-plat-Fix-xhci_plat-shutdown-sequence In-Reply-To: <20180417103226.GA8445@kroah.com> References: <20180417103226.GA8445@kroah.com> Message-ID: <9445d31a0d3a7e26bb6dc1807539ad6e@codeaurora.org> Sender: stable-owner@vger.kernel.org List-ID: 在 2018-04-17 18:32，Greg KH 写道： > On Tue, Apr 17, 2018 at 11:32:42AM +0800, leiwan@codeaurora.org wrote: >> >> xhci-plat Shutdown callback should check HCD_FLAG_HW_ACCESSIBLE >> before accessing any register. This should avoid hung with access >> controllers which support runtime suspend >> >> This can fix for issue of https://patchwork.kernel.org/patch/10339317/ >> corresponding upload in CAF: >> https://source.codeaurora.org/quic/la/kernel/msm-4.4/commit/?h=LV.HB.1.1.5-03810-8x96.0&id=a7a5307ee04ad349d365ad50f304605a9cd9bd0a >> >> full patch refer attachment. >> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c >> index 9b27798..bdf914d 100644 >> --- a/drivers/usb/host/xhci.c >> +++ b/drivers/usb/host/xhci.c >> @@ -702,6 +702,10 @@ static void xhci_shutdown(struct usb_hcd *hcd) >> usb_disable_xhci_ports(to_pci_dev(hcd->self.sysdev)); >> >> spin_lock_irq(&xhci->lock); >> + if (!HCD_HW_ACCESSIBLE(hcd)) { >> + spin_unlock_irq(&xhci->lock); >> + return; >> + } >> xhci_halt(xhci); > > A blank line after the if statement? > >> [lei]yes > What about all of the other places in this driver that you should also > check for this? Look at the other host controllers, shouldn't you > mirror what they are doing? > >> [lei]I checked other usb host module shutdown and suspend workflow. >> All usb host driver need to check hw accessable before >> read/write usb register especially in runtime PM case.. > And this needs a Fixes: tag, along with a cc: stable so as to properly > get backported as this is broken in some stable kernels right now. > >> [lei] Added by v2 patch > thanks, > > greg k-h From c03697fa259ab38d1002598ec2ccfac37607ca0b Mon Sep 17 00:00:00 2001 From: Lei wang Date: Tue, 17 Apr 2018 10:55:35 +0800 Subject: [PATCH v2] xhci: plat: Fix xhci_plat shutdown hung xhci-plat Shutdown callback should check HCD_FLAG_HW_ACCESSIBLE before accessing any register. This should avoid hung with access controllers which support runtime suspend Fixes: b07c12517f2a ("xhci: plat: Register shutdown for xhci_plat") Cc: Signed-off-by: Lei wang --- drivers/usb/host/xhci.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 9b27798..bdf914d 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -702,6 +702,10 @@ static void xhci_shutdown(struct usb_hcd *hcd) usb_disable_xhci_ports(to_pci_dev(hcd->self.sysdev)); spin_lock_irq(&xhci->lock); + if (!HCD_HW_ACCESSIBLE(hcd)) { + spin_unlock_irq(&xhci->lock); + return; + } xhci_halt(xhci); /* Workaround for spurious wakeups at shutdown with HSW */ if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) -- 1.9.1