[PATCH v7 0/2] Add PCIe support for i.MX6q

Hi Bjorn,

On Thu, Oct 10, 2013 at 4:25 AM, Marek Vasut [off-list ref] wrote:

quoted

In the meantime, this is what I see upon probe with V6 of the patches:

Linux version 3.12.0-rc2-next-20130927+
[...]
imx6q-pcie 1ffc000.pcie: phy link never came up
PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io  0x1000-0x10000]
pci_bus 0000:00: root bus resource [mem 0x01000000-0x01efffff]
pci_bus 0000:00: No busn resource found for root bus, will use [bus
00-ff]

This indicates a bug in your host bridge driver.  You must supply the
bus number range claimed by the host bridge.  There's no way the PCI
core can figure that out itself.  We do assume [bus 00-ff], but that's
only a fallback and will prevent multi-host bridge configurations from
working.

Ah, thanks for this information, this is very helpful! I implemented mx6 PCIe 
driver for U-Boot and this is my topology (detected by U-Boot)

  00:01.0     - 16c3:abcd - Bridge device
   01:00.0    - 12d8:2303 - Bridge device
    02:01.0   - 12d8:2303 - Bridge device
     03:00.0  - 8086:1531 - Network controller
    02:02.0   - 12d8:2303 - Bridge device

(The mnenomic is BUS:DEV.FN)

So I shouldn't even touch 0000:00:00.0 in Linux, but use 0000:00:01.0 as that's 
the root hub (16c3:abcd), no?

quoted

PCI: bus0: Fast back to back transfers disabled
PCI: bus1: Fast back to back transfers enabled
PCI: Device 0000:00:00.0 not available because of resource collisions
pcieport: probe of 0000:00:00.0 failed with error -22

If you boot with "ignore_loglevel", you should see more details about
this device, including the BAR values we read from it.  Based on
pcibios_enable_device() in arch/arm/kernel/bios32.c, my guess is that
00:00.0 has an uninitialized BAR (maybe it is in power-on state), and
you didn't do anything to assign the BAR before trying to bind the
pcieport driver to it.  You might be missing a call to
pci_bus_assign_resources() or pci_assign_unassigned_resources().

Will check this, thank you!

quoted

pci 0000:00:00.0: BAR 0: assigned [mem 0x01000000-0x010fffff]
pci 0000:00:00.0: BAR 6: assigned [mem 0x01100000-0x0110ffff pref]
pci 0000:00:00.0: PCI bridge to [bus 01]
pci 0000:00:00.0: PCI bridge to [bus 01]

Is this line normal/expected? Is this related to the PCIe switch I have
there? pcieport: probe of 0000:00:00.0 failed with error -22

Thank you for your help!

Best regards,
Marek Vasut

Best regards,
Marek Vasut