From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bh-25.webhostbox.net ([208.91.199.152]:44189 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753937AbbHFCWt (ORCPT ); Wed, 5 Aug 2015 22:22:49 -0400 Message-ID: <55C2C4F4.1040600@roeck-us.net> Date: Wed, 05 Aug 2015 19:22:44 -0700 From: Guenter Roeck MIME-Version: 1.0 To: Yinghai Lu CC: Bjorn Helgaas , "linux-pci@vger.kernel.org" , Linux Kernel Mailing List , Lorenzo Pieralisi Subject: Re: [PATCH v3] PCI: Only enable IO window if supported References: <1438308908-12259-1-git-send-email-linux@roeck-us.net> In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: On 08/05/2015 06:38 PM, Yinghai Lu wrote: > On Wed, Aug 5, 2015 at 6:14 PM, Yinghai Lu wrote: >> >> It only can avoid warning with bridge, and still have warning on >> devices under the bridge. >> >> also would have problem on transparent bridges, like >> >> BRIDGE_A ---- BRIDGE_AA----DEVICE_AA >> | >> \-- BRIDGE_AB ---DEVICE_AB >> >> if only BRIDGE_A and BRIDGE_AA are transparent, and BRIDGE_AB is not. >> >> and if pci_bridge_supports_io() return false for BRIDGE_A. >> >> We will have all three bridges have PCI_BUS_FLAGS_SUPPORTS_IO cleared. >> so all will not been sized and will not get assigned io port resource. >> >> later DEVICE_AA could root bus io port as parent, and get io resource assigned. >> but DEVICE_AB will not get assigned. >> >> so we should get rid of pci_bridge_supports_io(), and just check root >> resource IO port. > > I would suggest this version instead: > > Subject: [PATCH] PCI: Only try to assign io port only if root bus support that > Bjorn had asked me to move the IO support check out of pci_bridge_check_ranges(). It looks like you want to keep it there. Can you explain your reasons ? Sorry, I just don't understand. Guenter