Re: [PATCH v4 10/10] arm64: tegra: Enable PCIe on Jetson TX1

[Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

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On Mon, Nov 28, 2016 at 06:54:44PM +0200, Mikko Perttunen wrote:
> Testing this series with a Jetson TX1 + r8168e PCI-E card, it /almost/
> works.. Relevant parts of bootlog:
> 
> [    1.876191] tegra-pcie 1003000.pcie-controller: 4x1, 1x1 configuration
> [    1.884200] tegra-pcie 1003000.pcie-controller: probing port 0, using 4
> lanes
> [    1.893368] tegra-pcie 1003000.pcie-controller: Slot present pin change,
> signature: 00000008
> [    1.948049] tegra-pcie 1003000.pcie-controller: probing port 1, using 1
> lanes
> [    1.957209] tegra-pcie 1003000.pcie-controller: Slot present pin change,
> signature: 00000000
> [    2.367748] tegra-pcie 1003000.pcie-controller: link 1 down, retrying
> [    2.778307] tegra-pcie 1003000.pcie-controller: link 1 down, retrying
> [    3.188888] tegra-pcie 1003000.pcie-controller: link 1 down, retrying
> [    3.197344] tegra-pcie 1003000.pcie-controller: link 1 down, ignoring
> [    3.203931] tegra-pcie 1003000.pcie-controller: PCI host bridge to bus
> 0000:00
> [    3.211160] pci_bus 0000:00: root bus resource [io  0x0000-0xffff]
> [    3.217343] pci_bus 0000:00: root bus resource [mem
> 0x13000000-0x1fffffff]
> [    3.224218] pci_bus 0000:00: root bus resource [mem 0x20000000-0x3fffffff
> pref]
> [    3.231525] pci_bus 0000:00: root bus resource [bus 00-ff]
> [    3.237380] pci 0000:00:01.0: bridge configuration invalid ([bus 00-00]),
> reconfiguring
> [    3.254499] pci 0000:00:01.0: BAR 14: assigned [mem
> 0x13000000-0x130fffff]
> [    3.261389] pci 0000:00:01.0: BAR 15: assigned [mem 0x20000000-0x200fffff
> 64bit pref]
> [    3.269220] pci 0000:00:01.0: BAR 13: assigned [io  0x1000-0x1fff]
> [    3.275412] pci 0000:01:00.0: BAR 4: assigned [mem 0x20000000-0x20003fff
> 64bit pref]
> [    3.283172] pci 0000:01:00.0: BAR 2: assigned [mem 0x13000000-0x13000fff
> 64bit]
> [    3.290498] pci 0000:01:00.0: BAR 0: assigned [io  0x1000-0x10ff]
> [    3.296596] pci 0000:00:01.0: PCI bridge to [bus 01]
> [    3.301568] pci 0000:00:01.0:   bridge window [io  0x1000-0x1fff]
> [    3.307666] pci 0000:00:01.0:   bridge window [mem 0x13000000-0x130fffff]
> [    3.314454] pci 0000:00:01.0:   bridge window [mem 0x20000000-0x200fffff
> 64bit pref]
> [    3.322213] pci 0000:00:01.0: nv_msi_ht_cap_quirk didn't locate host
> bridge
> [    3.329257] pcieport 0000:00:01.0: enabling device (0000 -> 0003)
> [    3.335572] pcieport 0000:00:01.0: Signaling PME through PCIe PME
> interrupt
> [    3.342537] pci 0000:01:00.0: Signaling PME through PCIe PME interrupt
> [    3.349256] r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded
> [    3.354858] r8169 0000:01:00.0: enabling device (0000 -> 0003)
> [    3.361460] r8169 0000:01:00.0 eth0: RTL8168e/8111e at
> 0xffff000008eae000, 98:de:d0:04:25:14, XID 0c200000 IRQ 348
> [    3.371812] r8169 0000:01:00.0 eth0: jumbo features [frames: 9200 bytes,
> tx checksumming: ko]
> 
> then
> 
> [    3.706240] tegra-mc 70019000.memory-controller: afiw: write
> @0x000000007a484000: EMEM address decode error (EMEM decode error)
> [    3.717747] r8169 0000:01:00.0 eth0: link down

Hmm... that's very odd. It seems like for some reason the PCIe
controller wants to access memory that's below the DRAM. Do you happen
to have the SMMU enabled for PCIe? Can you try adding some debug prints
to the networking driver to find out where this address is coming from?

> The card is alive though, the transfer LED is blinking according to incoming
> traffic, I assume; we can also see that the driver is able to access the hw
> to some extent. The kernel version is 4.9rc7 with just this series on top.
> The same board/card also works in U-boot.

I've tested this on a recent linux-next, so perhaps that's something
else to try out. I wouldn't expect v4.9-rc7 to have any issues with a
PCI network driver, but who knows.

Thanks,
Thierry

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