RE: [PATCH 1/2 v3] pci-hyperv: properly handle pci bus remove

[Long Li]

Hi Bjorn

This patch is still pending. The patch has been ack'ed.

Do you want me to resend this patch?

Thanks

Long

> -----Original Message-----
> From: KY Srinivasan
> Sent: Friday, November 11, 2016 2:21 PM
> To: Bjorn Helgaas <helgaas@xxxxxxxxxx>; Long Li <longli@xxxxxxxxxxxxx>
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; Bjorn Helgaas
> <bhelgaas@xxxxxxxxxx>; devel@xxxxxxxxxxxxxxxxxxxxxx; linux-
> pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Long Li
> <longli@xxxxxxxxxxxxx>
> Subject: RE: [PATCH 1/2 v3] pci-hyperv: properly handle pci bus remove
> 
> 
> 
> > -----Original Message-----
> > From: Bjorn Helgaas [mailto:helgaas@xxxxxxxxxx]
> > Sent: Friday, November 11, 2016 1:04 PM
> > To: Long Li <longli@xxxxxxxxxxxxx>
> > Cc: KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang
> > <haiyangz@xxxxxxxxxxxxx>; Bjorn Helgaas <bhelgaas@xxxxxxxxxx>;
> > devel@xxxxxxxxxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; Long Li <longli@xxxxxxxxxxxxx>
> > Subject: Re: [PATCH 1/2 v3] pci-hyperv: properly handle pci bus remove
> >
> > On Mon, Oct 03, 2016 at 11:42:47PM -0700, Long Li wrote:
> > > From: Long Li <longli@xxxxxxxxxxxxx>
> > >
> > > hv_pci_devices_present is called in hv_pci_remove when we remove a
> > > PCI
> > device from host (e.g. by disabling SRIOV on a device). In
> > hv_pci_remove, the bus is already removed before the call, so we don't
> > need to rescan the bus in the workqueue scheduled from
> > hv_pci_devices_present. By introducing status hv_pcibus_removed, we
> can avoid this situation.
> > >
> > > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> > > Tested-by: Cathy Avery <cavery@xxxxxxxxxx>
> > > Reported-by: Xiaofeng Wang <xiaofwan@xxxxxxxxxx>
> 
> Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> 
> 
> >
> > I need an ack from the Hyper-V maintainers.  I see acks for previous
> > versions, but I don't know whether you've changed things that would
> > invalidate those acks.  If the acks still apply, please include them
> > and repost these patches.
> >
> > Also, please run "git log --oneline drivers/pci/host/pci-hyperv.c" and
> > make your subject line match the previous ones.
> >
> > > ---
> > >  drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> > >  1 file changed, 17 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/pci/host/pci-hyperv.c
> > > b/drivers/pci/host/pci-hyperv.c index a8deeca..4a37598 100644
> > > --- a/drivers/pci/host/pci-hyperv.c
> > > +++ b/drivers/pci/host/pci-hyperv.c
> > > @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> > >  	hv_pcibus_init = 0,
> > >  	hv_pcibus_probed,
> > >  	hv_pcibus_installed,
> > > +	hv_pcibus_removed,
> > >  	hv_pcibus_maximum
> > >  };
> > >
> > > @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct
> > work_struct *work)
> > >  		put_pcichild(hpdev, hv_pcidev_ref_initial);
> > >  	}
> > >
> > > -	/* Tell the core to rescan bus because there may have been changes.
> > */
> > > -	if (hbus->state == hv_pcibus_installed) {
> > > +	switch (hbus->state) {
> > > +	case hv_pcibus_installed:
> > > +		/*
> > > +		 * Tell the core to rescan bus
> > > +		 * because there may have been changes.
> > > +		 */
> > >  		pci_lock_rescan_remove();
> > >  		pci_scan_child_bus(hbus->pci_bus);
> > >  		pci_unlock_rescan_remove();
> > > -	} else {
> > > +		break;
> > > +
> > > +	case hv_pcibus_init:
> > > +	case hv_pcibus_probed:
> > >  		survey_child_resources(hbus);
> > > +		break;
> > > +
> > > +	default:
> > > +		break;
> > >  	}
> > >
> > >  	up(&hbus->enum_sem);
> > > @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> > >  	hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> > >  	if (!hbus)
> > >  		return -ENOMEM;
> > > +	hbus->state = hv_pcibus_init;
> > >
> > >  	/*
> > >  	 * The PCI bus "domain" is what is called "segment" in ACPI and @@
> > > -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> > >  		pci_stop_root_bus(hbus->pci_bus);
> > >  		pci_remove_root_bus(hbus->pci_bus);
> > >  		pci_unlock_rescan_remove();
> > > +		hbus->state = hv_pcibus_removed;
> > >  	}
> > >
> > >  	ret = hv_send_resources_released(hdev);
> > > --
> > > 1.8.5.6
> > >
> > > --
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