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 7FFF0C4332F for ; Sat, 10 Dec 2022 00:53:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229761AbiLJAxi (ORCPT ); Fri, 9 Dec 2022 19:53:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbiLJAxh (ORCPT ); Fri, 9 Dec 2022 19:53:37 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA0F09764E; Fri, 9 Dec 2022 16:53:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1670633616; x=1702169616; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=TnfD0mZeAmpMteacT6BU2lU8PJ8wEOvUACMJDMCbvLU=; b=Nw1ViKztQzGLZwlBg+YKIZwWaQeK3D8s07fimCl4UJqaKcxCdCz3MfIt 4DAAXX23lyx6/hyRdK7prInqXIlhqJpF2j26Ocz7Mu8MTC82SEuNTn2FQ U7hpgDzaMURZt9EGu25D6UFX7l1nYeFt7zlObJWc75bEjH/MNAddBkJfD pvsHC6BQcYAii1sLMN2qwIX5cwSl3/iROuyG+IuJ3Sw4k5EzpsBWoWBCb 5hxN3s8s9NCV+vUHVF5TsE88zpb/WgQS1CNJkeIxa3hLRTueoCwZKOMg4 1vlupKUVdqwbmonDX8Zc7vLqb/lwAb7yc+1sKSajSfvkXVig9gmx52RAf Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10556"; a="403833308" X-IronPort-AV: E=Sophos;i="5.96,232,1665471600"; d="scan'208";a="403833308" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Dec 2022 16:53:35 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10556"; a="597895810" X-IronPort-AV: E=Sophos;i="5.96,232,1665471600"; d="scan'208";a="597895810" Received: from rrode-mobl1.amr.corp.intel.com (HELO [10.251.24.37]) ([10.251.24.37]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Dec 2022 16:53:35 -0800 Message-ID: <240a1988-4d4a-87dd-8d4f-f9e198660175@linux.intel.com> Date: Fri, 9 Dec 2022 16:53:34 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.4.2 Subject: Re: [PATCH v3] PCI/portdrv: Allow AER service only for Root Ports & RCECs Content-Language: en-US To: Bjorn Helgaas , Mika Westerberg Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Helgaas References: <20221210002922.1749403-1-helgaas@kernel.org> From: Sathyanarayanan Kuppuswamy In-Reply-To: <20221210002922.1749403-1-helgaas@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 12/9/22 4:29 PM, Bjorn Helgaas wrote: > From: Bjorn Helgaas > > Previously portdrv allowed the AER service for any device with an AER > capability (assuming Linux had control of AER) even though the AER service > driver only attaches to Root Port and RCECs. > > Because get_port_device_capability() included AER for non-RP, non-RCEC > devices, we tried to initialize the AER IRQ even though these devices > don't generate AER interrupts. > > Intel DG1 and DG2 discrete graphics cards contain a switch leading to a > GPU. The switch supports AER but not MSI, so initializing an AER IRQ > failed, and portdrv failed to claim the switch port at all. The GPU itself > could be suspended, but the switch could not be put in a low-power state > because it had no driver. > > Don't allow the AER service on non-Root Port, non-Root Complex Event > Collector devices. This means we won't enable Bus Mastering if the device > doesn't require MSI, the AER service will not appear in sysfs, and the AER > service driver will not bind to the device. > > Link: https://lore.kernel.org/r/20221207084105.84947-1-mika.westerberg@linux.intel.com > Based-on-patch-by: Mika Westerberg > Signed-off-by: Bjorn Helgaas > --- Reviewed-by: Kuppuswamy Sathyanarayanan > > This is a v3 based on Mika's patch at > https://lore.kernel.org/r/20221207084105.84947-1-mika.westerberg@linux.intel.com > > I wouldn't normally kibbitz like this, but I'm hoping to squeeze this into > the v6.2 merge window. > > Changes from v2: > > * Test the device type in get_port_device_capability() instead of > pcie_init_service_irqs(). The benefits are to keep the device type > checking together (this is similar to the PME test), avoid enabling Bus > Mastering unnecessarily, avoid exposing the portdrv AER service in > sysfs, and preventing the AER service driver from binding to devices it > doesn't need to. > > drivers/pci/pcie/portdrv.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c > index a6c4225505d5..8b16e96ec15c 100644 > --- a/drivers/pci/pcie/portdrv.c > +++ b/drivers/pci/pcie/portdrv.c > @@ -232,7 +232,9 @@ static int get_port_device_capability(struct pci_dev *dev) > } > > #ifdef CONFIG_PCIEAER > - if (dev->aer_cap && pci_aer_available() && > + if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || > + pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) && > + dev->aer_cap && pci_aer_available() && > (pcie_ports_native || host->native_aer)) > services |= PCIE_PORT_SERVICE_AER; > #endif -- Sathyanarayanan Kuppuswamy Linux Kernel Developer