>> However when I boot Linux kernel (with 'igb' driver patched to >> recognize 8086:1531 VID:PID) on that board and run 'eepromARMtool' >> (Intel provided EEPROM programming tool) I can see it reading various >> registers correctly >> >> My questions are: >> - Is anyone currently using i.MX6 PCIe driver in 'next' branch? > > I didn't try the latest revision, but with v2015.10.0 PCIe on i.MX6 was > working fine. > >> - Has anyone seen similar behavior on this particular controller >> and discovered the root cause? >> > The symptoms you describe do look to me like the firmware on the i210 > device doesn't get initialized. Unfortunately I don't have any specific > pointers where to start searching for the root cause. > I kept looking into the issue and noticed one thing that Linux kernel does differently -- when handling PCI bridges it allocates bridge window before that PCI bridge's BAR windows in address space as can be seen below: [ 0.831099] imx6q-pcie 1ffc000.pcie: PCI host bridge to bus 0000:00 [ 0.837480] pci_bus 0000:00: root bus resource [io 0x1000-0x10000] [ 0.843878] pci_bus 0000:00: root bus resource [mem 0x01000000-0x01efffff] [ 0.850881] pci_bus 0000:00: root bus resource [bus 00-ff] [ 0.856913] PCI: bus0: Fast back to back transfers disabled [ 0.880182] PCI: bus1: Fast back to back transfers disabled [ 0.885980] pci 0000:00:00.0: BAR 8: assigned [mem 0x01000000-0x01bfffff] [ 0.892902] pci 0000:00:00.0: BAR 0: assigned [mem 0x01c00000-0x01cfffff] [ 0.899806] pci 0000:00:00.0: BAR 6: assigned [mem 0x01d00000-0x01d0ffff pref] [ 0.907154] pci 0000:00:00.0: BAR 7: assigned [io 0x1000-0x1fff] [ 0.913387] pci 0000:01:00.0: BAR 0: assigned [mem 0x01000000-0x017fffff] [ 0.920324] pci 0000:01:00.0: BAR 3: assigned [mem 0x01800000-0x01803fff] [ 0.927241] pci 0000:01:00.0: BAR 2: assigned [io 0x1000-0x101f] [ 0.933480] pci 0000:00:00.0: PCI bridge to [bus 01] [ 0.938553] pci 0000:00:00.0: bridge window [io 0x1000-0x1fff] [ 0.944772] pci 0000:00:00.0: bridge window [mem 0x01000000-0x01bfffff] [ 0.951984] pcieport 0000:00:00.0: Signaling PME through PCIe PME interrupt [ 0.959056] pci 0000:01:00.0: Signaling PME through PCIe PME interrupt When I tried emulating this behavior in Barebox by moving "setup_device(dev, 2)" from line 384 to be right after "postscan_setup_bridge(dev)" in "drivers/pci/pci.c" I was able to communicate with i210. I am bit hesitant to make a patch yet, since for the life of me I cannot explain this behavior, any thoughts on why this can be happening? Andrey _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
