On Mon, Aug 3, 2015 at 3:27 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > > You might have a host bridge driver that knows how to set up the > windows. Your dmesg logs mention altera_hps2fpga_bridge, which > doesn't seem to be in the upstream kernel, so I don't know what it > does. Sorry. Forgot to tell you it is based on the driver available at: http://rocketboards.org/foswiki/view/Projects/PCIeRootPortWithMSI I figured/hoped it was a general PCIe lack of understanding on my part and not something specifically related to the PCIe root complex driver. > In the other log ("08:00.0 not present at boot"), we actually *do* > enumerate an 08:00.0 device: > > pci 0000:08:00.0: [1d00:0000] type 00 class 0x00001d > pci 0000:08:00.0: reg 0x30: [mem 0x00001800-0x00001fff pref] Yea. Not sure what that is since there is no device physically present. PLX must be reserving the spot or something. > I don't know what this device is (lspci says "non-VGA unclassified > device") and it only requests 2K of space for an option ROM. And the > log doesn't include the part where you hot-add the real device -- > that's the interesting information should be. I added the dmesg for enumeration after hot-adding the device to the bugzilla entry. Don't want to omit the interesting part. > I see that you already boot with "pcie=hpmemsize=256M", but that > doesn't help in this case because it's only used for hotplug bridges, > and 02:0f.0 (the Downstream Port leading to bus 08) is not marked as > hotplug-capable: > > 02:0f.0 PCI bridge: PLX Technology, Inc. PEX 8619 > Capabilities: [68] Express (v2) Downstream Port (Slot+), MSI 00 > SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise- > > I think if you could get the PCI_EXP_SLTCAP_HPC bit set for 02:0f.0, > and you booted with "pcie=hpmemsize=256M", it would likely work. It's > possible it could be made to work even without that, but in general > it's hard to reserve the right amount of space for a bridge if you > don't know what might be plugged in later. This makes sense to me. I think I have enough information now to try to massage the PLX port into being a hotplug port and maybe everything will work. Thanks for yor help Bjorn! I have something to try now. Barry -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
