On Tue, Mar 29, 2016 at 9:13 AM, Roberto Fichera <kernel@xxxxxxxxxxxxx> wrote: > On 03/29/2016 05:10 PM, Tim Harvey wrote: >> Arnd, >> >> Right, on the IMX the MSI interrupt is GIC-120 which is also the >> legacy INTD and I do see that if I happen to put a radio in a slot >> where due to swizzling its pin1 becomes INTD (GIC-120) the interrupt >> does fire and the device works. Any other slot using GIC-123 (INTA), >> GIC-122 (INTB), or GIC-121 (INTC) never fires so its very possible >> that something in the designware core is masking out the legacy irqs. >> I would also think this was something IMX specific, but I really don't >> see any codepaths in pci-imx6.c that would cause that: a driver >> requesting a legacy PCI would get a GIC interrupt which is handled by >> the IMX6 gpc interrupt controller. >> >> Any dra7xxx, exynos, spear13xx, keystone, layerscape, hisi, qcom SoC >> users of designware PCIe core out there that can verify PCI MSI and >> legacy are both working at the same time? >> >> Lucas is the expert here and I believe he has the documentation for >> the designware core that Freescale doens't provide with the IMX6 >> documentation so hopefully he can provide some insight. He's the one >> that has authored all the MSI support and has been using it. >> >> I typically advise our users to 'not' enable MSI because >> architecturally you can spread 4 distinct legacy irq's across CPU's >> better than a single shared irq. > > Don't know if I'm facing similar problem, however devices connected in miniPCI slot behind > a PCIe-to-PCI bridge (MSI is disabled) using INTA all is working ok, including shared IRQ. > In case of INTB will not work, and the GIC irq quite often get stuck. > Roberto, What board/platform is this and what does /proc/interrupts look like? This sounds like what would happen if the downstream interrupts on the PCIe-to-PCI bridge are not mapped properly as was the case with a board I support (in which case I had to work out a bootloader fixup that placed a non-standard interrupt-map in the device-tree for the bridge). What bridge are you using? Tim -- 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
