From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vJ0k42NmHzDq8f for ; Wed, 8 Feb 2017 10:22:36 +1100 (AEDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v17NDUia070212 for ; Tue, 7 Feb 2017 18:22:33 -0500 Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) by mx0a-001b2d01.pphosted.com with ESMTP id 28fphqjnff-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 07 Feb 2017 18:22:33 -0500 Received: from localhost by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 8 Feb 2017 09:22:30 +1000 Received: from d23relay08.au.ibm.com (d23relay08.au.ibm.com [9.185.71.33]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 3441F2CE8046 for ; Wed, 8 Feb 2017 10:22:28 +1100 (EST) Received: from d23av06.au.ibm.com (d23av06.au.ibm.com [9.190.235.151]) by d23relay08.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v17NMKtl23330894 for ; Wed, 8 Feb 2017 10:22:28 +1100 Received: from d23av06.au.ibm.com (localhost [127.0.0.1]) by d23av06.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v17NLtac003479 for ; Wed, 8 Feb 2017 10:21:55 +1100 Date: Wed, 8 Feb 2017 10:21:30 +1100 From: Gavin Shan To: Michael Ellerman Cc: Andrew Donnellan , Gavin Shan , linuxppc-dev@lists.ozlabs.org, imunsie@au1.ibm.com Subject: Re: [PATCH] drivers/misc/cxl: Avoid unnecessary error message Reply-To: Gavin Shan References: <1485834216-25191-1-git-send-email-gwshan@linux.vnet.ibm.com> <43e94920-66a0-88af-81fe-5733ad7cf743@au1.ibm.com> <871svab6fj.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <871svab6fj.fsf@concordia.ellerman.id.au> Message-Id: <20170207232130.GB10885@gwshan> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Feb 07, 2017 at 10:12:48PM +1100, Michael Ellerman wrote: >Andrew Donnellan writes: .../... >> The effect of this patch is to copy the memory resources from the *real* >> PHB to the vPHB, as given through the device tree. It shouldn't have any >> practical effect other than squashing this message. > >It sounds a bit backward to me. If we don't need the resources then >why have them? > >If we have code that thinks that's an error, than maybe that's what >needs fixing, or special casing for the vPHB? > Yeah, vPHB is a special case. There are basically two stages in PCI enumeration: probing and then resource assignment. vPHB is different from *real* PHB as the resource assignment is skipped on it. So vPHB doesn't need any resources to be populated. However, there is a check in probing stage and it's where the warning message comes from. drivers/misc/cxl/vphb.c::cxl_pci_vphb_add() arch/powerpc/kernel/pci-common.c::pcibios_scan_phb() pcibios_setup_phb_resources() static void pcibios_setup_phb_resources(struct pci_controller *hose, struct list_head *resources) { : for (i = 0; i < 3; ++i) { res = &hose->mem_resources[i]; if (!res->flags) { if (i == 0) printk(KERN_ERR "PCI: Memory resource 0 not set for " "host bridge %s (domain %d)\n", hose->dn->full_name, hose->global_number); continue; } : } Alternatively, we can replace prink(KERN_ERR) with pr_debug(). It's going to affect all PHBs including the real ones. Andrew and Michael, what do you think? :-) Thanks, Gavin