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 00B4AC04A95 for ; Wed, 28 Sep 2022 21:46:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234509AbiI1VqE (ORCPT ); Wed, 28 Sep 2022 17:46:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234517AbiI1VqB (ORCPT ); Wed, 28 Sep 2022 17:46:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E35090802; Wed, 28 Sep 2022 14:45:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 94E7B61FE6; Wed, 28 Sep 2022 21:45:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA194C433D6; Wed, 28 Sep 2022 21:45:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664401559; bh=ZImTpZIu1Oe/UGX3YTfpv34oAqqGDVjjQAwxKC7tMS0=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=MFj660pBOrMYHQoas/9wCNwNCnFH8hiE2aXMVVjE621A0IAbNHp9IDdTCc2/ymELq EPKfRfEI6vwNjcDL0/72pbOhTpWWPv0D2We2IuSV8En7RBMUQK57X8ZG+XY7YEp8U1 cdZwKL3rLoI8euNyPPw6bITZQBDYNTGUW6rMdsbAFcp94IeGZvKvkyU3j/bI/OT7pZ 0evYbRVsI00MtictJpn/qLofVAYigAFymh6WrOisW0e5mHzc0Bi4EUv8dzFDbRPLoy J5xbrKMorcy9XQPFt4ZSJjBUjFJMugBK/QMUvfu88XAOMgQgjlf29xTLu9TfMTLYfH 7ieEQ6DSQwILw== Date: Wed, 28 Sep 2022 16:45:57 -0500 From: Bjorn Helgaas To: Kai-Heng Feng Cc: bhelgaas@google.com, sathyanarayanan.kuppuswamy@linux.intel.com, linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, koba.ko@canonical.com, Oliver O'Halloran , mika.westerberg@linux.intel.com Subject: Re: [PATCH 2/3] PCI/AER: Disable AER service on suspend when IRQ is shared with PME Message-ID: <20220928214557.GA1840266@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220727013255.269815-2-kai.heng.feng@canonical.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Jul 27, 2022 at 09:32:51AM +0800, Kai-Heng Feng wrote: > PCIe service that shares IRQ with PME may cause spurious wakeup on > system suspend. > > PCIe Base Spec 5.0, section 5.2 "Link State Power Management" states > that TLP and DLLP transmission is disabled for a Link in L2/L3 Ready > (D3hot), L2 (D3cold with aux power) and L3 (D3cold), so we don't lose > much here to disable AER during system suspend. > > This is very similar to previous attempts to suspend AER and DPC [1], > but with a different reason. > > [1] https://lore.kernel.org/linux-pci/20220408153159.106741-1-kai.heng.feng@canonical.com/ > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216295 > > Signed-off-by: Kai-Heng Feng > --- > drivers/pci/pcie/aer.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c > index 7952e5efd6cf3..60cc373754af2 100644 > --- a/drivers/pci/pcie/aer.c > +++ b/drivers/pci/pcie/aer.c > @@ -1372,6 +1372,26 @@ static int aer_probe(struct pcie_device *dev) > return 0; > } > > +static int aer_suspend(struct pcie_device *dev) > +{ > + struct aer_rpc *rpc = get_service_data(dev); > + > + if (dev->shared_pme_irq) > + aer_disable_rootport(rpc); aer_disable_rootport() seems like it might be overkill. IIUC, what we want to do here is disable AER interrupts, which should only require clearing ROOT_PORT_INTR_ON_MESG_MASK in PCI_ERR_ROOT_COMMAND. In addition to clearing ROOT_PORT_INTR_ON_MESG_MASK, aer_disable_rootport() traverses the whole hierarchy, clearing PCI_EXP_AER_FLAGS (CERE | NFERE | FERE | URRE) in PCI_EXP_DEVCTL. I don't think these DEVCTL bits control interrupt generation, so I don't know why we need to touch them. aer_disable_rootport() also clears PCI_ERR_ROOT_STATUS, which I think we should not do during suspend either. We might want to clear it on resume (which we already do in pci_restore_state()), but I think generally we should preserve error information as long as it doesn't cause trouble. Your thoughts please :) > + > + return 0; > +} > + > +static int aer_resume(struct pcie_device *dev) > +{ > + struct aer_rpc *rpc = get_service_data(dev); > + > + if (dev->shared_pme_irq) > + aer_enable_rootport(rpc); > + > + return 0; > +} > + > /** > * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP > * @dev: pointer to Root Port, RCEC, or RCiEP > @@ -1441,8 +1461,9 @@ static struct pcie_port_service_driver aerdriver = { > .name = "aer", > .port_type = PCIE_ANY_PORT, > .service = PCIE_PORT_SERVICE_AER, > - > .probe = aer_probe, > + .suspend = aer_suspend, > + .resume = aer_resume, > .remove = aer_remove, > }; > > -- > 2.36.1 >