On Wed, Jan 17, 2024 at 5:22 PM Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
>
> Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > In order to introduce PCI power-sequencing, we need to create platform
> > devices for child nodes of the port node. They will get matched against
> > the pwrseq drivers (if one exists) and then the actual PCI device will
> > reuse the node once it's detected on the bus.
> >
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> [..]
> > diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
> > index d749ea8250d6..77be0630b7b3 100644
> > --- a/drivers/pci/remove.c
> > +++ b/drivers/pci/remove.c
> > @@ -1,6 +1,7 @@
> > // SPDX-License-Identifier: GPL-2.0
> > #include <linux/pci.h>
> > #include <linux/module.h>
> > +#include <linux/of_platform.h>
> > #include "pci.h"
> >
> > static void pci_free_resources(struct pci_dev *dev)
> > @@ -18,11 +19,11 @@ static void pci_stop_dev(struct pci_dev *dev)
> > pci_pme_active(dev, false);
> >
> > if (pci_dev_is_added(dev)) {
> > -
> > device_release_driver(&dev->dev);
> > pci_proc_detach_device(dev);
> > pci_remove_sysfs_dev_files(dev);
> > of_pci_remove_node(dev);
> > + of_platform_depopulate(&dev->dev);
> >
> > pci_dev_assign_added(dev, false);
>
> Why is pci_stop_dev() not in strict reverse order of
> pci_bus_add_device()? I see that pci_dev_assign_added() was already not
> in reverse "add" order before your change, but I otherwise would have
> expected of_platform_depopulate() before of_pci_remove_node() (assumed
> paired with of_pci_make_dev_node()).
The naming here is confusing but the two have nothing in common. One
is used by CONFIG_PCI_DYNAMIC_OF_NODES to *create* new DT nodes for
detected PCI devices. The one I'm adding, creates power sequencing
*devices* (no nodes) for *existing* DT nodes.
So the order is not really relevant here but I can change in v2.
Bartosz
