Re: [PATCH] pci: shpchp: set the bridge busmaster if MSI are enabled

[Marcel Apfelbaum <marcel.apfelbaum@xxxxxxxxx>]

On 19/07/2017 16:36, Marcel Apfelbaum wrote:
> On 18/07/2017 17:12, Aleksandr Bezzubikov wrote:
> > An MSI-based SHPC built in PCI bridges can configure hotplugged devices
> > only if they notify the bridge with MSI.
> > But they can't trigger interrupt without the bridge being busmaster,
> > that's why it should be enabled.
>
> Hi Aleksandr,
>
> Hot-plugging an empty bridge does require making it bus-master,
> otherwise we end up with an unusable pci brigde.
>
> > Signed-off-by: Aleksandr Bezzubikov <zuban32s@xxxxxxxxx>
> > ---
> >   drivers/pci/hotplug/shpchp_hpc.c | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/pci/hotplug/shpchp_hpc.c 
> > b/drivers/pci/hotplug/shpchp_hpc.c
> > index de0ea47..e5824c7 100644
> > --- a/drivers/pci/hotplug/shpchp_hpc.c
> > +++ b/drivers/pci/hotplug/shpchp_hpc.c
> > @@ -1062,6 +1062,8 @@ int shpc_init(struct controller *ctrl, struct 
> > pci_dev *pdev)
> >           if (rc) {
> >               ctrl_info(ctrl, "Can't get msi for the hotplug 
> > controller\n");
> >               ctrl_info(ctrl, "Use INTx for the hotplug controller\n");
> > +        } else {
> > +            pci_set_master(pdev);
> >           }
> >           rc = request_irq(ctrl->pci_dev->irq, shpc_isr, IRQF_SHARED,
>
>
> I am not really familiar with the shpc code,
> but the change looks OK to me.
>
> Reviewed-by: Marcel Apfelbaum <marcel@xxxxxxxxxx>

Hi,

Since is a fix:
Cc: stable@xxxxxxxxxxxxxxx

Thanks,
Marcel

> Thanks,
> Marcel