Re: commit e38c0a1f breaks powerpc boards with uli1575 chip

From: Rob Herring
Date: Wed Dec 18 2013 - 13:40:31 EST


[fixed DT maillist address]

On 12/17/2013 01:35 AM, Nikita Yushchenko wrote:
> Hi
>
> While trying to make freescale p2020ds and mpc8572ds boards working with mainline kernel, I faced that commit
> e38c0a1f (Handle #address-cells > 2 specially) breaks things with these boards.

Good to see this broke in v3.7 and is just now found...

>
> 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 !
>
> Either e38c0a1f should be reverted, or uli1575 (and perhaps other similar devices) have to be described in device
> trees differently.

Reverting would break Tegra PCIe, but you should not have to change the
DT either. So we need a solution.

Is this something like this sufficient to fix it?

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 4b9317b..378aebd 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -74,7 +74,7 @@ static u64 of_bus_default_map(__be32 *addr, const
__be32 *range,
* mapping doesn't specify a physical address. Rather, the address
* specifies an identifier that must match exactly.
*/
- if (na > 2 && memcmp(range, addr, na * 4) != 0)
+ if (na > 2 && memcmp(range, addr, (na - 2) * 4) != 0)
return OF_BAD_ADDR;

if (da < cp || da >= (cp + s))


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