On Mon, Dec 16, 2024 at 10:45:21AM +0530, Manivannan Sadhasivam wrote: > On Sun, Dec 15, 2024 at 06:19:22PM +0100, Lukas Wunner wrote: > > On Tue, Dec 10, 2024 at 03:25:24PM +0530, Manivannan Sadhasivam wrote: > > > diff --git a/drivers/pci/pwrctrl/core.c b/drivers/pci/pwrctrl/core.c > > > index 2fb174db91e5..9cc7e2b7f2b5 100644 > > > --- a/drivers/pci/pwrctrl/core.c > > > +++ b/drivers/pci/pwrctrl/core.c > > > @@ -44,7 +44,7 @@ static void rescan_work_func(struct work_struct *work) > > > struct pci_pwrctrl, work); > > > > > > pci_lock_rescan_remove(); > > > - pci_rescan_bus(to_pci_dev(pwrctrl->dev->parent)->bus); > > > + pci_rescan_bus(to_pci_host_bridge(pwrctrl->dev->parent)->bus); > > > pci_unlock_rescan_remove(); > > > } > > > > Remind me, what's the purpose of this? I'm guessing that it > > recursively creates the platform devices below the newly > > powered up device, is that correct? If so, is it still > > necessary? Doesn't the new approach automatically create > > those devices upon their enumeration? > > If the pwrctrl driver is available at the time of platform device creation, > this is not needed. But if the driver is not available at that time and > probed later, then we need to rescan the bus to enumerate the devices. I see. Sounds like this can be made conditional on the caller being a module. I think you could achieve this with the following in pci_pwrctl_device_set_ready(): - schedule_work(&pwrctl->work); + if (is_module_address(_RET_IP_)) + schedule_work(&pwrctl->work); Though you'd also have to declare pci_pwrctl_device_set_ready() "__attribute__((always_inline))" so that it gets inlined into devm_pci_pwrctl_device_set_ready() and the condition works there as well. I'm wondering whether the bus notifier is still necessary with the new scheme. Since the power control device is instantiated and destroyed in unison with the pci_dev, can't the device link always be created on instantiation of the power control device? Thanks, Lukas
