From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uma Krishnan Subject: Re: [PATCH 1/7] cxlflash: Simplify PCI registration Date: Tue, 8 Mar 2016 11:54:46 -0600 Message-ID: <56DF11E6.2010907@linux.vnet.ibm.com> References: <1457128424-53017-1-git-send-email-ukrishn@linux.vnet.ibm.com> <1457128520-53056-1-git-send-email-ukrishn@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from e32.co.us.ibm.com ([32.97.110.150]:41949 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750905AbcCHRyt (ORCPT ); Tue, 8 Mar 2016 12:54:49 -0500 Received: from localhost by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 8 Mar 2016 10:54:48 -0700 Received: from b03cxnp08025.gho.boulder.ibm.com (b03cxnp08025.gho.boulder.ibm.com [9.17.130.17]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 5DE413E40052 for ; Tue, 8 Mar 2016 10:54:46 -0700 (MST) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u28HskTT45940956 for ; Tue, 8 Mar 2016 10:54:46 -0700 Received: from d03av01.boulder.ibm.com (localhost [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u28HsiVY016999 for ; Tue, 8 Mar 2016 10:54:46 -0700 In-Reply-To: <1457128520-53056-1-git-send-email-ukrishn@linux.vnet.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org, James Bottomley , "Martin K. Petersen" , "Matthew R. Ochs" , "Manoj N. Kumar" Cc: linuxppc-dev@lists.ozlabs.org, Brian King , Ian Munsie , Andrew Donnellan , Frederic Barrat , Christophe Lombard On 3/4/2016 3:55 PM, Uma Krishnan wrote: > From: "Manoj N. Kumar" > > The calls to pci_request_regions(), pci_resource_start(), > pci_set_dma_mask(), pci_set_master() and pci_save_state() are all > unnecessary for the IBM CXL flash adapter since data buffers > are not required to be mapped to the device's memory. > > The use of services such as pci_set_dma_mask() are problematic on > hypervisor managed systems as the IBM CXL flash adapter is operating > under a virtual PCI Host Bridge (virtual PHB) which does not support > these services. > > cxlflash 0001:00:00.0: init_pci: Failed to set PCI DMA mask rc=-5 > > The resolution is to simplify init_pci(), to a point where it does the > bare minimum (pci_enable_device). Similarly, remove the call the > pci_release_regions() from cxlflash_remove(). > > Signed-off-by: Manoj N. Kumar Reviewed-by: Uma Krishnan