[PATCH] PCI: mvebu: setup BAR0 to internal-regs

Thomas Petazzoni thomas.petazzoni at bootlin.com
Mon Jun 22 14:40:33 EDT 2020


On Mon, 22 Jun 2020 12:25:16 -0500
Bjorn Helgaas <helgaas at kernel.org> wrote:

> > As a result of the requirement above, without this patch, MSI won't
> > function and therefore some devices won't operate properly without
> > pci=nomsi.  
> Does that mean MSIs never worked at all with mvebu?

They definitely worked. I think what happens is that this register was
normally setup by the vendor-specific bootloader, and thanks to
firmware initialization, Linux had MSIs working properly.

With other bootloaders that initialize the PCIe block differently, or
even not at all, it became clear this init was missing in Linux.

Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering

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