-----Original Message-----
From: Arnd Bergmann [mailto:arnd at arndb.de]
Sent: 08 February 2016 13:48
To: linux-arm-kernel at lists.infradead.org
Cc: Gabriele Paoloni; Guohanjun (Hanjun Guo); Wangzhou (B); liudongdong
(C); Linuxarm; qiujiang; bhelgaas at google.com;
Lorenzo.Pieralisi at arm.com; tn at semihalf.com; linux-pci at vger.kernel.org;
linux-kernel at vger.kernel.org; xuwei (O); linux-acpi at vger.kernel.org;
jcm at redhat.com; zhangjukuo; Liguozhu (Kenneth)
Subject: Re: [RFC PATCH v2 2/3] PCI: hisi: Make the HiSilicon PCIe host
controller ECAM compliant

On Monday 08 February 2016 12:41:03 Gabriele Paoloni wrote:

quoted

From: gabriele paoloni <redacted>

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 <redacted>
Signed-off-by: Dongdong Liu <redacted>

Doesn't this break backwards compatibility?

Well Hip05/Hip06 SoCs are used into evaluation boards
For the Estuary project.

https://github.com/hisilicon/estuary

As this new driver gets upstream we'll merge this new driver into estuary
and release a new version of the firmware to support it.

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.

You are right, for some reason in this patchset I missed the Documentation
update that I posted in the previous one, i.e.:

--- a/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt

@@ -23,8 +23,8 @@ Optional properties:
 Hip05 Example (note that Hip06 is the same except compatible):
 	pcie at 0xb0080000 {
 		compatible = "hisilicon,hip05-pcie", "snps,dw-pcie";
-		reg = <0 0xb0080000 0 0x10000>, <0x220 0x00000000 0 0x2000>;
-		reg-names = "rc_dbi", "config";
+		reg = <0 0xb0080000 0 0x10000>, <0x220 0x00100000 0 0x0f00000>;
+		reg-names = "rc_dbi", "ecam-cfg";

I will fix this in v3

Thanks

Gab 

	Arnd