From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:43838) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gqnC8-0007vi-4h for qemu-devel@nongnu.org; Mon, 04 Feb 2019 17:58:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gqnC5-0004cl-SZ for qemu-devel@nongnu.org; Mon, 04 Feb 2019 17:58:27 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:56470) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gqnC5-0004ay-AN for qemu-devel@nongnu.org; Mon, 04 Feb 2019 17:58:25 -0500 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x14MnKtN015192 for ; Mon, 4 Feb 2019 17:58:23 -0500 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qexa4gn8c-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 04 Feb 2019 17:58:22 -0500 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 4 Feb 2019 22:58:21 -0000 References: <20190130155733.32742-1-david@redhat.com> <20190130155733.32742-2-david@redhat.com> From: Collin Walling Date: Mon, 4 Feb 2019 17:58:18 -0500 MIME-Version: 1.0 In-Reply-To: <20190130155733.32742-2-david@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: <191e8d6f-31a7-93bd-376c-783a9dde90ba@linux.ibm.com> Subject: Re: [Qemu-devel] [PATCH v2 1/6] s390x/pci: Fix primary bus number for PCI bridges List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand , qemu-devel@nongnu.org Cc: Thomas Huth , Pierre Morel , Cornelia Huck , Christian Borntraeger , qemu-s390x@nongnu.org, Richard Henderson On 1/30/19 10:57 AM, David Hildenbrand wrote: > The primary bus number corresponds always to the bus number of the > bus the bridge is attached to. > > Right now, if we have two bridges attached to the same bus (e.g. root > bus) this is however not the case. The first bridge will have primary > bus 0, the second bridge primary bus 1, which is wrong. Fix the assignment. > > While at it, drop setting the PCI_SUBORDINATE_BUS temporarily to 0xff. > Setting it temporarily to that value (as discussed e.g. in [1]), is > only relevant for a running system that probes the buses. The value is > effectively unused for us just doing a DFS. > > Also add a comment why we have to reassign during every reset (which I > found to be surprising. > > Please note that hotplugging of bridges is in general still broken, will > be fixed next. > > [1] http://www.science.unitn.it/~fiorella/guidelinux/tlk/node76.html > > Reviewed-by: Thomas Huth > Signed-off-by: David Hildenbrand > --- Reviewed-by: Collin Walling