Re: [PATCH v2] pci: ensure valid link status bits for downstream ports

[Sebastian Ott]

Hello Michael, Marcel,

On Tue, 3 Dec 2024, Alex Williamson wrote:

> On Tue,  3 Dec 2024 13:19:28 +0100
> Sebastian Ott <sebott@redhat.com> wrote:
>
> > PCI hotplug for downstream endpoints on arm fails because Linux'
> > PCIe hotplug driver doesn't like the QEMU provided LNKSTA:
> >
> >   pcieport 0000:08:01.0: pciehp: Slot(2): Card present
> >   pcieport 0000:08:01.0: pciehp: Slot(2): Link Up
> >   pcieport 0000:08:01.0: pciehp: Slot(2): Cannot train link: status 0x2000
> >
> > There's 2 cases where LNKSTA isn't setup properly:
> > * the downstream device has no express capability
> > * max link width of the bridge is 0
> >
> > Move the sanity checks added via 88c869198aa63
> > ("pci: Sanity test minimum downstream LNKSTA") outside of the
> > branch to make sure downstream ports always have a valid LNKSTA.
> >
> > Signed-off-by: Sebastian Ott <sebott@redhat.com>
> > Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
> > ---
> >  hw/pci/pcie.c | 12 ++++++++----
> >  1 file changed, 8 insertions(+), 4 deletions(-)
>
> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>

Can you pick this up for the next qemu release, please? It fixes PCI
hotplug for downstream endpoints on arm.

Thanks,
Sebastian