Thread (66 messages) 66 messages, 10 authors, 2014-05-28

Re: [PATCH 05/17] pci: host: pcie-dra7xx: add support for pcie-dra7xx controller

From: Arnd Bergmann <arnd@arndb.de>
Date: 2014-05-08 09:17:10
Also in: linux-arm-kernel, linux-omap, linux-pci, lkml

On Thursday 08 May 2014 17:56:38 Jingoo Han wrote:
On Wednesday, May 07, 2014 6:26 PM, Arnd Bergmann wrote:
quoted
On Wednesday 07 May 2014 14:52:47 Kishon Vijay Abraham I wrote:
quoted
On Tuesday 06 May 2014 10:05 PM, Jason Gunthorpe wrote:
quoted
On Tue, May 06, 2014 at 07:03:51PM +0530, Kishon Vijay Abraham I wrote:
quoted
+Example:
+pcie@51000000 {
+    compatible = "ti,dra7xx-pcie";
+    reg = <0x51002000 0x14c>, <0x51000000 0x2000>;
+    reg-names = "ti_conf", "rc_dbics";
+    interrupts = <0 232 0x4>, <0 233 0x4>;
+    #address-cells = >;
+    #size-cells = <2>;
+    device_type = "pci";
+    ti,device_type = >;
+    ranges = <0x00000800 0 0x20001000 0x20001000 0 0x00002000  /* Configuration Space */
Configuration space should not show up in the ranges, please don't
copy that mistake from other drivers, put it in reg.
But then it needs pcie-designware.c to be modified and it will be breaking
other platforms no?
I think the pcie-designware driver should be changed to allow either way.
Ideally we would deprecate the existing method in a way that for new front-ends
it doesn't work, but the old front-ends can still deal with it but also work
if you put it into the reg property.
(+cc Pratyush Anand, Thierry Reding)

Hi Arnd,

Thank you for your comment.
Do you mean the case of Tegra PCIe as below?

./arch/arm/boot/dts/tegra20.dts
        pcie-controller@80003000 {
                ...
                reg = <0x80003000 0x00000800   /* PADS registers */
                         0x80003800 0x00000200   /* AFI registers */
                         0x90000000 0x10000000>; /* configuration space */
                ...
                ranges = <0x82000000 0 0x80000000 0x80000000 0 0x00001000   /* port 0 registers */
                        0x82000000 0 0x80001000 0x80001000 0 0x00001000   /* port 1 registers */
                        0x81000000 0 0          0x82000000 0 0x00010000   /* downstream I/O */
                        0x82000000 0 0xa0000000 0xa0000000 0 0x08000000   /* non-prefetchable memory */
                        0xc2000000 0 0xa8000000 0xa8000000 0 0x18000000>; /* prefetchable memory */
                ...

./drivers/pci/host/pci-tegra.c
        /* request configuration space, but remap later, on demand */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cs");
        ...
        pcie->cs = devm_request_mem_region(pcie->dev, res->start,
                                                resource_size(res), res->name);
Yes, that is how the config space should be handled normally.

	Arnd
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