On Fri, Aug 30, 2024 at 9:14 AM Frank Li <Frank.li@xxxxxxx> wrote: > > On Fri, Aug 30, 2024 at 09:03:09AM -0700, Tim Harvey wrote: > > On Thu, Aug 29, 2024 at 6:50 PM Hongxing Zhu <hongxing.zhu@xxxxxxx> wrote: > > > > > > > -----Original Message----- > > > > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> > > > > Sent: 2024年8月30日 5:23 > > > > To: tharvey@xxxxxxxxxxxxx; Hongxing Zhu <hongxing.zhu@xxxxxxx>; Lucas > > > > Stach <l.stach@xxxxxxxxxxxxxx> > > > > Cc: linux-pci@xxxxxxxxxxxxxxx > > > > Subject: Re: legacy PCI device behind a bridge not getting a valid IRQ on imx > > > > host controller > > > > > > > > [+cc Richard, Lucas, maintainers of IMX6 PCI] > > > > > > > > On Wed, Aug 28, 2024 at 02:40:33PM -0700, Tim Harvey wrote: > > > > > Greetings, > > > > > > > > > > I have a user that is using an IMX8MM SoC (dwc controller) with a > > > > > miniPCIe card that has a PEX8112 PCI-to-PCIe bridge to a legacy PCI > > > > > device and the device is not getting a valid interrupt. > > > > > > > > Does pci-imx6.c support INTx at all? > > > > > > > i.MX PCIe RC supports INTx. > > > Add pci=nomsi into kernel command line, can verify it when one endpoint > > > device is connected. > > > Based i.MX8MM EVK board and on NVME, MSI or INTx are enabled. > > > logs of MSI: > > > root@imx8_all:~# lspci > > > 00:00.0 PCI bridge: Synopsys, Inc. Device abcd (rev 01) > > > 01:00.0 Non-Volatile memory controller: Device 1e49:0021 (rev 01) > > > root@imx8_all:~# cat /proc/interrupts | grep MSI > > > 221: 0 0 0 0 PCI-MSI 0 Edge PCIe PME > > > 222: 14 0 0 0 PCI-MSI 524288 Edge nvme0q0 > > > 223: 382 0 0 0 PCI-MSI 524289 Edge nvme0q1 > > > 224: 115 0 0 0 PCI-MSI 524290 Edge nvme0q2 > > > 225: 521 0 0 0 PCI-MSI 524291 Edge nvme0q3 > > > 226: 53 0 0 0 PCI-MSI 524292 Edge nvme0q4 > > > > > > > Richard, > > > > off topic but I've seen in the IMX8MMRM a claim that it supports MSI-X > > but I have not seen this to be the case as you are showing above with > > an nvme that would clearly use MSI-X if available. > > IMX8MM should support MSI only. > Hi Frank, Thanks for clarifying this; I don't know why the IMX8MMRM and IMX8MPRM indicate they support MSI-X. I have the hardware in hand now as well as the out-of-tree driver that's being used. I can say there is nothing wrong here with legacy PCI interrupt mapping, if I write a skeleton driver that uses pci_resister_driver(struct pci_driver) its probe is called with an interrupt and request_irq on that interrupt succeeds just fine. The issue here is with the vendor's out-of-tree driver which instead is using pci_get_device() to scan the bus which returns a struct pci_dev * that doesn't have an irq assigned (like what is described in https://www.kernel.org/doc/html/v5.5/PCI/pci.html#how-to-find-pci-devices-manually). When using pci_get_device() when/how does pci_assign_irq() get called to assign the irq to the device? Best Regards, Tim
