Re: [PATCH 1/2] PCI: apple: Integrate pwrctrl API

On Tue, Jul 07, 2026 at 02:58:39PM +0100, Marc Zyngier wrote:
> On Tue, 07 Jul 2026 13:04:21 +0100,
> Yureka Lilian <[email protected]> wrote:
> > 
> > On 7/7/26 11:25, Marc Zyngier wrote:
> > > On Mon, 06 Jul 2026 23:38:27 +0100,
> > > Yureka Lilian <[email protected]> wrote:
> > >> Integrate the PCI pwrctrl framework into the Apple PCIe host driver to
> > >> provide standardized power management for PCI devices.
> > >> 
> > >> Notably, this allows enabling powering on the WiFi, SD card reader on
> > >> various Macs by means of the pwrctrl framework before probing the ports.
> > >> 
> > >> Previously, a custom solution for powering on the WiFi and SD card
> > >> reader was proposed[1], but we can now use the new pci-pwrctrl-generic
> > >> driver for this purpose.
> > >> 
> > >> Link[1]: https://lore.kernel.org/lkml/[email protected]/
> > >> 
> > > nit: this paragraph and the accompanying link don't belong in the
> > > commit message and should be moved below the --- mark or even better,
> > > to the cover letter.
> > ack, will leave it out of the commit message of the individual commit in v2
> > >> Signed-off-by: Yureka Lilian <[email protected]>
> > >> ---
> > >>   drivers/pci/controller/Kconfig      |  1 +
> > >>   drivers/pci/controller/pcie-apple.c | 16 ++++++++++++++++
> > >>   2 files changed, 17 insertions(+)
> > >> 
> > >> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> > >> index 2247709ef6d6..af64630d28fa 100644
> > >> --- a/drivers/pci/controller/Kconfig
> > >> +++ b/drivers/pci/controller/Kconfig
> > >> @@ -46,6 +46,7 @@ config PCIE_APPLE
> > >>   	depends on OF
> > >>   	depends on PCI_MSI
> > >>   	select PCI_HOST_COMMON
> > >> +	select PCI_PWRCTRL_GENERIC
> > >>   	select IRQ_MSI_LIB
> > >>   	help
> > >>   	  Say Y here if you want to enable PCIe controller support on Apple
> > >> diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
> > >> index c2cffc0659f4..db038a9d4831 100644
> > >> --- a/drivers/pci/controller/pcie-apple.c
> > >> +++ b/drivers/pci/controller/pcie-apple.c
> > >> @@ -30,6 +30,7 @@
> > >>   #include <linux/msi.h>
> > >>   #include <linux/of_irq.h>
> > >>   #include <linux/pci-ecam.h>
> > >> +#include <linux/pci-pwrctrl.h>
> > >>     #include "pci-host-common.h"
> > >>   @@ -825,6 +826,21 @@ static int apple_pcie_init(struct
> > >> pci_config_window *cfg)
> > >>   	if (WARN_ON(!pcie))
> > >>   		return -ENOENT;
> > >>   +	ret = pci_pwrctrl_create_devices(pcie->dev);
> > >> +	if (ret) {
> > >> +		dev_err(pcie->dev, "Failed to create pwrctrl devices: %pe\n", ret);
> > >> +		return ret;
> > >> +	}
> > >> +
> > >> +	ret = pci_pwrctrl_power_on_devices(pcie->dev);
> > >> +	if (ret) {
> > >> +		if (ret != -EPROBE_DEFER) {
> > >> +			dev_err(pcie->dev, "Failed to power on devices: %pe\n", ret);
> > >> +			pci_pwrctrl_destroy_devices(pcie->dev);
> > >> +		}
> > >> +		return ret;
> > >> +	}
> > >> +
> > > Why is this done globally while the whole driver works on a per-port
> > > basis, and that the proposed DT updates are also per port?
> > 
> > pci_pwrctrl_power_on_devices takes a struct device as parameter, but
> > pcie-apple does not allocate device structs for the individual ports.
> > This could be changed of course. But since pci_pwrctrl_* operate on
> > the subnodes recursively, it works just fine this way.
> 
> Works fine is one thing. Being consistent with the way the rest of the
> driver works is another. pci_pwrctrl_create_device() and
> pci_pwrctrl_power_on_device() appear to do exactly what would be
> required for a single port. They just needs to be exported made
> global/exported.
> 

I'm fine with exporting pci_pwrctrl_create_device() and
pci_pwrctrl_power_on_device() and calling them with per-port np.

- Mani

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