+ Rob
On Fri, Aug 23, 2024 at 11:33:22AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
>
> of_platform_depopulate() doesn't play nice with reused OF nodes - it
> ignores the ones that are not marked explicitly as populated and it may
> happen that the PCI device goes away before the platform device in which
> case the PCI core clears the OF_POPULATED bit. We need to
> unconditionally unregister the platform devices for child nodes when
> stopping the PCI device.
>
It sounds like the fix is in of_platform_depopulate() itself and this patch
works around the API issue in PCI driver.
Rob, is that correct?
- Mani
> Fixes: 8fb18619d910 ("PCI/pwrctl: Create platform devices for child OF nodes of the port node")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> ---
> drivers/pci/remove.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
> index 910387e5bdbf..4770cb87e3f0 100644
> --- a/drivers/pci/remove.c
> +++ b/drivers/pci/remove.c
> @@ -1,7 +1,10 @@
> // SPDX-License-Identifier: GPL-2.0
> #include <linux/pci.h>
> #include <linux/module.h>
> +#include <linux/of.h>
> #include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +
> #include "pci.h"
>
> static void pci_free_resources(struct pci_dev *dev)
> @@ -14,12 +17,25 @@ static void pci_free_resources(struct pci_dev *dev)
> }
> }
>
> +static int pci_pwrctl_unregister(struct device *dev, void *data)
> +{
> + struct device_node *pci_node = data, *plat_node = dev_of_node(dev);
> +
> + if (dev_is_platform(dev) && plat_node && plat_node == pci_node) {
> + of_device_unregister(to_platform_device(dev));
> + of_node_clear_flag(plat_node, OF_POPULATED);
> + }
> +
> + return 0;
> +}
> +
> static void pci_stop_dev(struct pci_dev *dev)
> {
> pci_pme_active(dev, false);
>
> if (pci_dev_is_added(dev)) {
> - of_platform_depopulate(&dev->dev);
> + device_for_each_child(dev->dev.parent, dev_of_node(&dev->dev),
> + pci_pwrctl_unregister);
> device_release_driver(&dev->dev);
> pci_proc_detach_device(dev);
> pci_remove_sysfs_dev_files(dev);
> --
> 2.43.0
>
--
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