Re: [RFC PATCH] PCI/portdrv: No need to call pci_disable_device() during shutdown

[Tiezhu Yang]

On 09/11/2020 04:21 AM, Bjorn Helgaas wrote:
> [+cc Huacai]
>
> On Thu, Sep 10, 2020 at 02:41:39PM -0500, Bjorn Helgaas wrote:
> > On Sat, Sep 05, 2020 at 04:33:26PM +0800, Tiezhu Yang wrote:
> > > After commit 745be2e700cd ("PCIe: portdrv: call pci_disable_device
> > > during remove") and commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe
> > > services during shutdown"), it also calls pci_disable_device() during
> > > shutdown, this seems unnecessary, so just remove it.
> > I would like to get rid of the portdrv completely by folding its
> > functionality into the PCI core itself, so there would be no portdrv
> > probe or remove.
> >
> > Does this solve a problem?

Yes, sometimes it can not shutdown or reboot normally with 
pci_disable_device().

> > If not, I'm inclined to just leave it
> > as-is for now.  But if it fixes something, we should do the fix, of
> > course.
> This looks awfully similar to [1], so I guess we *do* need to do
> something here.  I'll respond there since it has more details.
>
> [1] https://lore.kernel.org/r/1596268180-9114-1-git-send-email-chenhc@xxxxxxxxxx
>
> > > Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
> > > ---
> > >   drivers/pci/pcie/portdrv_core.c |  1 -
> > >   drivers/pci/pcie/portdrv_pci.c  | 14 +++++++++++++-
> > >   2 files changed, 13 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> > > index 50a9522..1991aca 100644
> > > --- a/drivers/pci/pcie/portdrv_core.c
> > > +++ b/drivers/pci/pcie/portdrv_core.c
> > > @@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev)
> > >   {
> > >   	device_for_each_child(&dev->dev, NULL, remove_iter);
> > >   	pci_free_irq_vectors(dev);
> > > -	pci_disable_device(dev);
> > >   }
> > >   
> > >   /**
> > > diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
> > > index 3a3ce40..cab37a8 100644
> > > --- a/drivers/pci/pcie/portdrv_pci.c
> > > +++ b/drivers/pci/pcie/portdrv_pci.c
> > > @@ -143,6 +143,18 @@ static void pcie_portdrv_remove(struct pci_dev *dev)
> > >   	}
> > >   
> > >   	pcie_port_device_remove(dev);
> > > +	pci_disable_device(dev);
> > > +}
> > > +
> > > +static void pcie_portdrv_shutdown(struct pci_dev *dev)
> > > +{
> > > +	if (pci_bridge_d3_possible(dev)) {
> > > +		pm_runtime_forbid(&dev->dev);
> > > +		pm_runtime_get_noresume(&dev->dev);
> > > +		pm_runtime_dont_use_autosuspend(&dev->dev);
> > > +	}
> > > +
> > > +	pcie_port_device_remove(dev);
> > >   }
> > >   
> > >   static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
> > > @@ -211,7 +223,7 @@ static struct pci_driver pcie_portdriver = {
> > >   
> > >   	.probe		= pcie_portdrv_probe,
> > >   	.remove		= pcie_portdrv_remove,
> > > -	.shutdown	= pcie_portdrv_remove,
> > > +	.shutdown	= pcie_portdrv_shutdown,
> > >   
> > >   	.err_handler	= &pcie_portdrv_err_handler,
> > >   
> > > --
> > > 2.1.0