linux-imx

Revert "of/address: Handle #address-cells > 2 specially"

This reverts commit e38c0a1fbc5803cbacdaac0557c70ac8ca5152e7.

Nikita Yushchenko reports:
While trying to make freescale p2020ds and  mpc8572ds boards working
with mainline kernel, I faced that commit e38c0a1f (Handle

Both these boards have uli1575 chip.
Corresponding part in device tree is something like

                uli1575@0 {
                        reg = <0x0 0x0 0x0 0x0 0x0>;
                        #size-cells = <2>;
                        #address-cells = <3>;
                        ranges = <0x2000000 0x0 0x80000000
                                  0x2000000 0x0 0x80000000
                                  0x0 0x20000000

                                  0x1000000 0x0 0x0
                                  0x1000000 0x0 0x0
                                  0x0 0x10000>;
                        isa@1e {
...

I.e. it has #address-cells = <3>

With commit e38c0a1f reverted, devices under uli1575 are registered
correctly, e.g. for rtc

OF: ** translation for device /pcie@ffe09000/pcie@0/uli1575@0/isa@1e/rtc@70 **
OF: bus is isa (na=2, ns=1) on /pcie@ffe09000/pcie@0/uli1575@0/isa@1e
OF: translating address: 00000001 00000070
OF: parent bus is default (na=3, ns=2) on /pcie@ffe09000/pcie@0/uli1575@0
OF: walking ranges...
OF: ISA map, cp=0, s=1000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 00000000 00000000 00000070
OF: parent bus is pci (na=3, ns=2) on /pcie@ffe09000/pcie@0
OF: walking ranges...
OF: default map, cp=a0000000, s=20000000, da=70
OF: default map, cp=0, s=10000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 01000000 00000000 00000070
OF: parent bus is pci (na=3, ns=2) on /pcie@ffe09000
OF: walking ranges...
OF: PCI map, cp=0, s=10000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 01000000 00000000 00000070
OF: parent bus is default (na=2, ns=2) on /
OF: walking ranges...
OF: PCI map, cp=0, s=10000, da=70
OF: parent translation for: 00000000 ffc10000
OF: with offset: 70
OF: one level translation: 00000000 ffc10070
OF: reached root node

With commit e38c0a1f in place, address translation fails:

OF: ** translation for device /pcie@ffe09000/pcie@0/uli1575@0/isa@1e/rtc@70 **
OF: bus is isa (na=2, ns=1) on /pcie@ffe09000/pcie@0/uli1575@0/isa@1e
OF: translating address: 00000001 00000070
OF: parent bus is default (na=3, ns=2) on /pcie@ffe09000/pcie@0/uli1575@0
OF: walking ranges...
OF: ISA map, cp=0, s=1000, da=70
OF: parent translation for: 01000000 00000000 00000000
OF: with offset: 70
OF: one level translation: 00000000 00000000 00000070
OF: parent bus is pci (na=3, ns=2) on /pcie@ffe09000/pcie@0
OF: walking ranges...
OF: default map, cp=a0000000, s=20000000, da=70
OF: default map, cp=0, s=10000, da=70
OF: not found !

Thierry Reding confirmed this commit was not needed after all:
"We ended up merging a different address representation for Tegra PCIe
and I've confirmed that reverting this commit doesn't cause any obvious
regressions. I think all other drivers in drivers/pci/host ended up
copying what we did on Tegra, so I wouldn't expect any other breakage
either."

There doesn't appear to be a simple way to support both behaviours, so
reverting this as nothing should be depending on the new behaviour.

Cc: stable@vger.kernel.org # v3.7+
Signed-off-by: Rob Herring <robh@kernel.org>