topic Re: MSI-X support, PCIe controller (pcie-designware.c) in i.MX Processors

MSI-X support, PCIe controller (pcie-designware.c)

graffiti — Fri, 10 Feb 2017 11:22:04 GMT

Hi,

I am developing a system using iMX6q where we have a requirement to support a PCIe device that requires MSI-X.

According to the imx6q reference manual the pcie bridge does support MSI-X, but the driver (pcie-designware.c) does not.

Specifically, in the dw_msi_setup_irq function we see:

if (desc->msi_attrib.is_msix)

return -EINVAL;

and tracing confirms that when we bring up the pcie device, that function is called explicitly not supporting MSI-X.

So my question: Is there a version of the pcie-designware.c driver, or an alternative driver, that supports MSI-X? (I have already checked fslc kernel and mainline latest version.)

Many thanks,

Kieran Tyrrell.

Re: MSI-X support, PCIe controller (pcie-designware.c)

igorpadykov — Fri, 10 Feb 2017 23:18:57 GMT

Hi Kieran

for MSI-X please check Chapter 40 PCI Express Root Complex Driverattached Linux Manual.

Best regards
igor
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Re: MSI-X support, PCIe controller (pcie-designware.c)

graffiti — Sat, 11 Feb 2017 09:28:02 GMT

Hi Igor,

Thanks for the reply, but I have checked the Linux Reference Manual and I see no reference to MSI-X.

In case of confusion, MSI is working fine, but we require MSI-X to support some extra features of the PCIe device.

Thanks, Kieran.

Re: MSI-X support, PCIe controller (pcie-designware.c)

igorpadykov — Sun, 12 Feb 2017 23:32:34 GMT

Hi Kieran

sorry, I overlooked MSI-X, seems you are right i.mx6q pcie module does not support it.

Best regards
igor