Re: legacy PCI device behind a bridge not getting a valid IRQ on imx host controller

[Tim Harvey <tharvey@gateworks.com>]

On Thu, Aug 29, 2024 at 6:50 PM Hongxing Zhu <hongxing.zhu@nxp.com> wrote:
>
> > -----Original Message-----
> > From: Bjorn Helgaas <helgaas@kernel.org>
> > Sent: 2024年8月30日 5:23
> > To: tharvey@gateworks.com; Hongxing Zhu <hongxing.zhu@nxp.com>; Lucas
> > Stach <l.stach@pengutronix.de>
> > Cc: linux-pci@vger.kernel.org
> > 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.

Does the IMX8MM hardware support MSI-X?

Best Regards,

Tim