Re: [PATCH 4/9] PCI: create platform devices for child OF nodes of the port node

From: Greg Kroah-Hartman
Date: Wed Jan 17 2024 - 11:46:05 EST


On Wed, Jan 17, 2024 at 05:07:43PM +0100, 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.

Ick, why a platform device? What is the parent of this device, a PCI
device? If so, then this can't be a platform device, as that's not what
it is, it's something else so make it a device of that type,.

> 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.

Reuse it how?

> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> ---
> drivers/pci/bus.c | 9 ++++++++-
> drivers/pci/remove.c | 3 ++-
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index 9c2137dae429..8ab07f711834 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -12,6 +12,7 @@
> #include <linux/errno.h>
> #include <linux/ioport.h>
> #include <linux/of.h>
> +#include <linux/of_platform.h>
> #include <linux/proc_fs.h>
> #include <linux/slab.h>
>
> @@ -342,8 +343,14 @@ void pci_bus_add_device(struct pci_dev *dev)
> */
> pcibios_bus_add_device(dev);
> pci_fixup_device(pci_fixup_final, dev);
> - if (pci_is_bridge(dev))
> + if (pci_is_bridge(dev)) {
> of_pci_make_dev_node(dev);
> + retval = of_platform_populate(dev->dev.of_node, NULL, NULL,
> + &dev->dev);

So this is a pci bridge device, not a platform device, please don't do
this, make it a real device of a new type.

thanks,

greg k-h