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 X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E2B2C82292 for ; Mon, 27 Apr 2020 22:51:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DEF4E20775 for ; Mon, 27 Apr 2020 22:51:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588027896; bh=whRFNUD4BZPg0hJwHb5jAU8zt3B+MFfDdFnuCfCh21Y=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=eWgBnBsVEDvUmQzoNfj92A07XHoG4AQp+T/e3YsYpwHwWIE64uN/AF1nT0UOyB/t/ L2oGDM/022s+hfxLGaE2TgmWQaSQwATIeQatAEXP924np3lMmZ7OnO/8xR6sQtE/G6 FWwSU3hCaaxKAcWbqd9hidv3e+sVY5VvF+lRB5iw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726315AbgD0Wvg (ORCPT ); Mon, 27 Apr 2020 18:51:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:37616 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbgD0Wvf (ORCPT ); Mon, 27 Apr 2020 18:51:35 -0400 Received: from localhost (mobile-166-175-187-210.mycingular.net [166.175.187.210]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5260020661; Mon, 27 Apr 2020 22:51:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588027894; bh=whRFNUD4BZPg0hJwHb5jAU8zt3B+MFfDdFnuCfCh21Y=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=jbJ+hBWbFaPZLAZpJBho1x6SwnoZZdRmb11ZCOfY2HQAirKqK3Ud5K3Tc2P/CEHxq YfIhwWgwPQzTeUCIK4Wz08oScj7EyiAqznu4rK0Hp9AVonP8uSBxI/HxMtjBtLKEKg /QFWHJDSaVjtDIOGeZy74eppVI0aTWQr0pZCSHyU= Date: Mon, 27 Apr 2020 17:51:32 -0500 From: Bjorn Helgaas To: Wei Hu Cc: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, lorenzo.pieralisi@arm.com, robh@kernel.org, linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, decui@microsoft.com, mikelley@microsoft.com Subject: Re: [PATCH] PCI: pci-hyperv: Retry PCI bus D0 entry when the first attempt failed with invalid device state 0xC0000184. Message-ID: <20200427225132.GA9339@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200426132430.1756-1-weh@microsoft.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Please pay attention to the changelog history and make yours match: $ git log --oneline drivers/pci/controller/pci-hyperv.c 1cf106d93245 ("PCI: hv: Introduce hv_msi_entry") 61bfd920abbf ("PCI: hv: Move retarget related structures into tlfs header") b00f80fcfaa0 ("PCI: hv: Move hypercall related definitions into tlfs header") 067fb6c97e7e ("PCI: hv: Replace zero-length array with flexible-array member") 999dd956d838 ("PCI: hv: Add support for protocol 1.3 and support PCI_BUS_RELATIONS2") f9ad0f361cf3 ("PCI: hv: Decouple the func definition in hv_dr_state from VSP message") 42c3d41832ef ("PCI: hv: Add missing kfree(hbus) in hv_pci_probe()'s error handling path") e658a4fea8ef ("PCI: hv: Remove unnecessary type casting from kzalloc") No period at end of subject. On Sun, Apr 26, 2020 at 09:24:30PM +0800, Wei Hu wrote: > In the case of kdump, the PCI device was not cleanly shut down > before the kdump kernel starts. This causes the initial > attempt of entering D0 state in the kdump kernel to fail with > invalid device state 0xC0000184 returned from Hyper-V host. > When this happens, explicitly call PCI bus exit and retry to > enter the D0 state. > > Also fix the PCI probe failure path to release the PCI device > resource properly. This sounds like two separate fixes that should be in separate patches? > Signed-off-by: Wei Hu > --- > drivers/pci/controller/pci-hyperv.c | 34 ++++++++++++++++++++++++++++- > 1 file changed, 33 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c > index e15022ff63e3..eb4781fa058d 100644 > --- a/drivers/pci/controller/pci-hyperv.c > +++ b/drivers/pci/controller/pci-hyperv.c > @@ -2736,6 +2736,10 @@ static void hv_free_config_window(struct hv_pcibus_device *hbus) > vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH); > } > > +#define STATUS_INVALID_DEVICE_STATE 0xC0000184 > + > +static int hv_pci_bus_exit(struct hv_device *hdev, bool hibernating); > + > /** > * hv_pci_enter_d0() - Bring the "bus" into the D0 power state > * @hdev: VMBus's tracking struct for this root PCI bus > @@ -2748,8 +2752,10 @@ static int hv_pci_enter_d0(struct hv_device *hdev) > struct pci_bus_d0_entry *d0_entry; > struct hv_pci_compl comp_pkt; > struct pci_packet *pkt; > + bool retry = true; > int ret; > > +enter_d0_retry: > /* > * Tell the host that the bus is ready to use, and moved into the > * powered-on state. This includes telling the host which region > @@ -2780,6 +2786,30 @@ static int hv_pci_enter_d0(struct hv_device *hdev) > dev_err(&hdev->device, > "PCI Pass-through VSP failed D0 Entry with status %x\n", > comp_pkt.completion_status); > + > + /* > + * In certain case (Kdump) the pci device of interest was > + * not cleanly shut down and resource is still held on host > + * side, the host could return STATUS_INVALID_DEVICE_STATE. > + * We need to explicitly request host to release the resource > + * and try to enter D0 again. > + */ > + if (comp_pkt.completion_status == STATUS_INVALID_DEVICE_STATE && > + retry) { > + ret = hv_pci_bus_exit(hdev, true); > + > + retry = false; > + > + if (ret == 0) { > + kfree(pkt); > + goto enter_d0_retry; > + } else { > + dev_err(&hdev->device, > + "PCI bus D0 exit failed with ret %d\n", > + ret); > + } > + } > + > ret = -EPROTO; > goto exit; > } > @@ -3136,7 +3166,7 @@ static int hv_pci_probe(struct hv_device *hdev, > > ret = hv_pci_allocate_bridge_windows(hbus); > if (ret) > - goto free_irq_domain; > + goto exit_d0; > > ret = hv_send_resources_allocated(hdev); > if (ret) > @@ -3154,6 +3184,8 @@ static int hv_pci_probe(struct hv_device *hdev, > > free_windows: > hv_pci_free_bridge_windows(hbus); > +exit_d0: > + (void) hv_pci_bus_exit(hdev, true); > free_irq_domain: > irq_domain_remove(hbus->irq_domain); > free_fwnode: > -- > 2.20.1 >