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 309B8C433F5 for ; Tue, 19 Apr 2022 14:44:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351088AbiDSOqj (ORCPT ); Tue, 19 Apr 2022 10:46:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34464 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351904AbiDSOqZ (ORCPT ); Tue, 19 Apr 2022 10:46:25 -0400 Received: from netrider.rowland.org (netrider.rowland.org [192.131.102.5]) by lindbergh.monkeyblade.net (Postfix) with SMTP id B4F883A71A for ; Tue, 19 Apr 2022 07:43:18 -0700 (PDT) Received: (qmail 594300 invoked by uid 1000); 19 Apr 2022 10:43:02 -0400 Date: Tue, 19 Apr 2022 10:43:02 -0400 From: Alan Stern To: Evan Green Cc: Greg Kroah-Hartman , Thomas Gleixner , Mathias Nyman , Rajat Jain , Bjorn Helgaas , "Rafael J. Wysocki" , Youngjin Jang , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH v2 2/2] USB: hcd-pci: Fully suspend across freeze/thaw cycle Message-ID: References: <20220418210046.2060937-1-evgreen@chromium.org> <20220418135819.v2.2.I8226c7fdae88329ef70957b96a39b346c69a914e@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220418135819.v2.2.I8226c7fdae88329ef70957b96a39b346c69a914e@changeid> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 18, 2022 at 02:00:46PM -0700, Evan Green wrote: > The documentation for the freeze() method says that it "should quiesce > the device so that it doesn't generate IRQs or DMA". The unspoken > consequence of not doing this is that MSIs aimed at non-boot CPUs may > get fully lost if they're sent during the period where the target CPU is > offline. > > The current callbacks for USB HCD do not fully quiesce interrupts, > specifically on XHCI. Change to use the full suspend/resume flow for > freeze/thaw to ensure interrupts are fully quiesced. This fixes issues > where USB devices fail to thaw during hibernation because XHCI misses > its interrupt and cannot recover. > > Signed-off-by: Evan Green > > --- Acked-by: Alan Stern > Changes in v2: > - Added the patch modifying the remote wakeup state That wasn't a change to this patch. No matter. > - Removed the change to freeze_noirq/thaw_noirq > > drivers/usb/core/hcd-pci.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c > index 8176bc81a635d6..ae5e6d572376be 100644 > --- a/drivers/usb/core/hcd-pci.c > +++ b/drivers/usb/core/hcd-pci.c > @@ -616,10 +616,10 @@ const struct dev_pm_ops usb_hcd_pci_pm_ops = { > .suspend_noirq = hcd_pci_suspend_noirq, > .resume_noirq = hcd_pci_resume_noirq, > .resume = hcd_pci_resume, > - .freeze = check_root_hub_suspended, > + .freeze = hcd_pci_suspend, > .freeze_noirq = check_root_hub_suspended, > .thaw_noirq = NULL, > - .thaw = NULL, > + .thaw = hcd_pci_resume, > .poweroff = hcd_pci_suspend, > .poweroff_noirq = hcd_pci_suspend_noirq, > .restore_noirq = hcd_pci_resume_noirq,