forked from luck/tmp_suning_uos_patched
32136568a9
I've encountered a serious problem with PCI config space access on Au1x000
platforms with recent 2.6.x-kernel. With 2.4.31 the same hardware works fine.
So I was looking for the differences:
Symptoms:
- no PCI-device is seen on bootup though two or three cards are present
- lspci output is empty
- OR: lspci shows 20 times the same device
(- OR: in some slot-configurations it worked anyhow)
System(s):
1. platform with Au1500 and three PCI-devices (actually a mycable XXS1500
with backplane for three PCI-devices)
2. platform with Au1550 and two PCI-devices (custom board)
Debugging:
I digged down to the config_access() of the au1xxx-processors in
arch/mips/pci/ops-au1000.c and switched on DEBUG.
The code of config_access() seems to be almost the same as of the
2.4.x-kernel. But the "pci_cfg_vm->addr" returned by get_vm_area(0x2000, 0)
once on booting is different. That's of course not forbidden. But the
alignment seems to be wrong. In my case, I received:
2.4.31: pci_cfg_vm->addr = c0000000
2.6.18-rc5: pci_cfg_vm->addr = c0101000
To make it short: With 2.6.x it fails on the first config-access with:
"PCI ERR detected: status 83a00356".
Fixup:
My fix is now, to use the VM_IOREMAP-flag in the get_vm_area call. This flag
seems to be introduced in mm/vmalloc.c a long time ago (in 2.6.7-bk13, I
found in gitweb).
Now, the returned address is pci_cfg_vm->addr = c0104000 and everything works
fine.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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|---|---|---|
| .. | ||
| fixup-atlas.c | ||
| fixup-au1000.c | ||
| fixup-capcella.c | ||
| fixup-cobalt.c | ||
| fixup-ddb5477.c | ||
| fixup-emma2rh.c | ||
| fixup-ev64120.c | ||
| fixup-ev96100.c | ||
| fixup-excite.c | ||
| fixup-ip32.c | ||
| fixup-ite8172g.c | ||
| fixup-ivr.c | ||
| fixup-jaguar.c | ||
| fixup-jmr3927.c | ||
| fixup-malta.c | ||
| fixup-mpc30x.c | ||
| fixup-ocelot-c.c | ||
| fixup-ocelot-g.c | ||
| fixup-ocelot.c | ||
| fixup-ocelot3.c | ||
| fixup-pnx8550.c | ||
| fixup-rbtx4927.c | ||
| fixup-sb1250.c | ||
| fixup-sni.c | ||
| fixup-tb0219.c | ||
| fixup-tb0226.c | ||
| fixup-tb0287.c | ||
| fixup-tx4938.c | ||
| fixup-vr4133.c | ||
| fixup-wrppmc.c | ||
| fixup-yosemite.c | ||
| Makefile | ||
| ops-au1000.c | ||
| ops-bonito64.c | ||
| ops-bridge.c | ||
| ops-ddb5477.c | ||
| ops-emma2rh.c | ||
| ops-gt64111.c | ||
| ops-gt64120.c | ||
| ops-gt96100.c | ||
| ops-it8172.c | ||
| ops-mace.c | ||
| ops-marvell.c | ||
| ops-msc.c | ||
| ops-nile4.c | ||
| ops-pnx8550.c | ||
| ops-sni.c | ||
| ops-titan-ht.c | ||
| ops-titan.c | ||
| ops-tx3927.c | ||
| ops-tx4927.c | ||
| ops-tx4938.c | ||
| ops-vr41xx.c | ||
| pci-bcm1480.c | ||
| pci-bcm1480ht.c | ||
| pci-ddb5477.c | ||
| pci-emma2rh.c | ||
| pci-ev96100.c | ||
| pci-excite.c | ||
| pci-ip27.c | ||
| pci-ip32.c | ||
| pci-jmr3927.c | ||
| pci-lasat.c | ||
| pci-ocelot-c.c | ||
| pci-ocelot-g.c | ||
| pci-ocelot.c | ||
| pci-sb1250.c | ||
| pci-vr41xx.c | ||
| pci-vr41xx.h | ||
| pci-yosemite.c | ||
| pci.c | ||