From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [RFC PATCH v2 2/3] PCI: hisi: Make the HiSilicon PCIe host controller ECAM compliant Date: Mon, 08 Feb 2016 14:48:18 +0100 Message-ID: <3532826.pJr5R5Xa4c@wuerfel> References: <1454935264-6076-1-git-send-email-gabriele.paoloni@huawei.com> <1454935264-6076-3-git-send-email-gabriele.paoloni@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1454935264-6076-3-git-send-email-gabriele.paoloni@huawei.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org Cc: Gabriele Paoloni , guohanjun@huawei.com, wangzhou1@hisilicon.com, liudongdong3@huawei.com, linuxarm@huawei.com, qiujiang@huawei.com, bhelgaas@google.com, Lorenzo.Pieralisi@arm.com, tn@semihalf.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, xuwei5@hisilicon.com, linux-acpi@vger.kernel.org, jcm@redhat.com, zhangjukuo@huawei.com, liguozhu@hisilicon.com List-Id: linux-acpi@vger.kernel.org On Monday 08 February 2016 12:41:03 Gabriele Paoloni wrote: > From: gabriele paoloni > > This patch modifies the current Hip05/Hip06 PCIe host controller > driver to make it ECAM compliant. This is needed in preparation > for the ACPI based driver to allow both DT and ACPI drivers to > use the same BIOS (that configure the Designware iATUs). > > Signed-off-by: Gabriele Paoloni > Signed-off-by: Dongdong Liu > Doesn't this break backwards compatibility? I think you need to use a new compatible string in the firmware if you change the register layout, and then change the driver to support both the old and the new layout. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Mon, 08 Feb 2016 14:48:18 +0100 Subject: [RFC PATCH v2 2/3] PCI: hisi: Make the HiSilicon PCIe host controller ECAM compliant In-Reply-To: <1454935264-6076-3-git-send-email-gabriele.paoloni@huawei.com> References: <1454935264-6076-1-git-send-email-gabriele.paoloni@huawei.com> <1454935264-6076-3-git-send-email-gabriele.paoloni@huawei.com> Message-ID: <3532826.pJr5R5Xa4c@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 08 February 2016 12:41:03 Gabriele Paoloni wrote: > From: gabriele paoloni > > This patch modifies the current Hip05/Hip06 PCIe host controller > driver to make it ECAM compliant. This is needed in preparation > for the ACPI based driver to allow both DT and ACPI drivers to > use the same BIOS (that configure the Designware iATUs). > > Signed-off-by: Gabriele Paoloni > Signed-off-by: Dongdong Liu > Doesn't this break backwards compatibility? I think you need to use a new compatible string in the firmware if you change the register layout, and then change the driver to support both the old and the new layout. Arnd