On 2018-12-06 9:50 a.m., Lucas Stach wrote: > Am Donnerstag, den 06.12.2018, 09:45 -0600 schrieb Robert Hancock: >> On 2018-12-06 2:10 a.m., Baruch Siach wrote: >>> Hi Andrey, >>> >>> Adding Robert Hancock who reported[1] on a PCIe MSI issue with i.MX6. >>> >>> Andrey Smirnov writes: >>> >>>> Building a kernel with CONFIG_PCI_IMX6=y, but CONFIG_PCIEPORTBUS=n >>>> produces a system where built-in PCIE bridge (16c3:abcd) isn't bound >>>> to pcieport driver. This, in turn, results in a PCIE bus that is >>>> capable of enumerating attached PCIE device, but lacks functional >>>> interrupt support. >>> >>> Robert, does that fix your issue? >> >> Unfortunately, no.. in fact the situation on my setup is even worse with >> CONFIG_PCIEPORTBUS enabled: Not only does MSI still not function, but >> now INTx interrupts are somehow broken as well - no interrupts are >> received. The IRQ information shown in /proc/interrupts is correct, but >> the count remains stubbornly at 0. > > That's expected. The port services will use an MSI IRQ when available > and due to a design issue with the DWC PCIe it will not forward any > legacy IRQs if any MSI is in use. If any of the PCIe devices in your > system are unable to work with MSI IRQs, you must boot with "nomsi" on > the kernel command line set. That seems like an unfortunate design choice on their part.. well that would probably argue against adding this as a hard dependency then, if non-MSI-supporting PCIe devices can't work with default boot options with that set. I'm looking into testing with an NXP Smart Devices board and some PCIe cards to see if I can verify whether MSI works on those or not, since we currently don't have a way to independently verify that the MSI implementation in our FPGA is working or whether another PCIe device works with MSI (the FPGA is integrated on the system board). -- Robert Hancock Senior Software Developer SED Systems Email: hancock@xxxxxxxxxxxxx
