On Wed, Oct 28, 2020 at 7:21 PM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
>
> Rob Herring <robh@xxxxxxxxxx> writes:
> > No other host driver sets the PCI_MSI_FLAGS_ENABLE bit, so it must not
> > be necessary. If it is, a comment is needed.
>
> Yeah, but git blame directly points to:
>
> 75cb8d20c112 ("PCI: imx: Enable MSI from downstream components")
I think I did read this at some point and then forgot about it when I
made the change later...
> Which has a pretty long explanation. The relevant bit probably being:
>
> ... on i.MX6, the MSI Enable bit controls delivery of MSI interrupts
> from components below the Root Port.
The thing is that all seems not i.MX6 specific but DWC specific given
MSI handling is contained within the DWC block. So I don't see how
this could be an integration difference.
So maybe everyone else is still just setting CONFIG_PCIEPORTBUS
typically and haven't noticed? Is it correct for the host driver to
set MSI enable?
Rob
