From f1536585588ba630c533b6ffbca8ad8424aa5c39 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 23 Aug 2024 11:33:22 +0200 Subject: PCI: Don't rely on of_platform_depopulate() for reused OF-nodes of_platform_depopulate() doesn't play nicely 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. Unconditionally unregister the platform devices for child nodes when stopping the PCI device. Link: https://lore.kernel.org/r/20240823093323.33450-2-brgl@bgdev.pl Fixes: 8fb18619d910 ("PCI/pwrctl: Create platform devices for child OF nodes of the port node") Signed-off-by: Bartosz Golaszewski Signed-off-by: Bjorn Helgaas Acked-by: Manivannan Sadhasivam --- 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 #include +#include #include +#include + #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); -- cgit From 8f62819aaace77dd85037ae766eb767f8c4417ce Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 23 Aug 2024 11:33:23 +0200 Subject: PCI/pwrctl: Rescan bus on a separate thread If we trigger the bus rescan from sysfs, we'll try to lock the PCI rescan mutex recursively and deadlock - the platform device will be populated and probed on the same thread that handles the sysfs write. Add a workqueue to the pwrctl code on which we schedule the rescan for controlled PCI devices. While at it: add a new interface for initializing the pwrctl context where we'd now assign the parent device address and initialize the workqueue. Link: https://lore.kernel.org/r/20240823093323.33450-3-brgl@bgdev.pl Fixes: 4565d2652a37 ("PCI/pwrctl: Add PCI power control core code") Reported-by: Konrad Dybcio Signed-off-by: Bartosz Golaszewski Signed-off-by: Bjorn Helgaas Reviewed-by: Manivannan Sadhasivam --- drivers/pci/pwrctl/core.c | 26 +++++++++++++++++++++++--- drivers/pci/pwrctl/pci-pwrctl-pwrseq.c | 2 +- include/linux/pci-pwrctl.h | 3 +++ 3 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/pci/pwrctl/core.c b/drivers/pci/pwrctl/core.c index feca26ad2f6a..01d913b60316 100644 --- a/drivers/pci/pwrctl/core.c +++ b/drivers/pci/pwrctl/core.c @@ -48,6 +48,28 @@ static int pci_pwrctl_notify(struct notifier_block *nb, unsigned long action, return NOTIFY_DONE; } +static void rescan_work_func(struct work_struct *work) +{ + struct pci_pwrctl *pwrctl = container_of(work, struct pci_pwrctl, work); + + pci_lock_rescan_remove(); + pci_rescan_bus(to_pci_dev(pwrctl->dev->parent)->bus); + pci_unlock_rescan_remove(); +} + +/** + * pci_pwrctl_init() - Initialize the PCI power control context struct + * + * @pwrctl: PCI power control data + * @dev: Parent device + */ +void pci_pwrctl_init(struct pci_pwrctl *pwrctl, struct device *dev) +{ + pwrctl->dev = dev; + INIT_WORK(&pwrctl->work, rescan_work_func); +} +EXPORT_SYMBOL_GPL(pci_pwrctl_init); + /** * pci_pwrctl_device_set_ready() - Notify the pwrctl subsystem that the PCI * device is powered-up and ready to be detected. @@ -74,9 +96,7 @@ int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl) if (ret) return ret; - pci_lock_rescan_remove(); - pci_rescan_bus(to_pci_dev(pwrctl->dev->parent)->bus); - pci_unlock_rescan_remove(); + schedule_work(&pwrctl->work); return 0; } diff --git a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c index c7a113a76c0c..f07758c9edad 100644 --- a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c +++ b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c @@ -50,7 +50,7 @@ static int pci_pwrctl_pwrseq_probe(struct platform_device *pdev) if (ret) return ret; - data->ctx.dev = dev; + pci_pwrctl_init(&data->ctx, dev); ret = devm_pci_pwrctl_device_set_ready(dev, &data->ctx); if (ret) diff --git a/include/linux/pci-pwrctl.h b/include/linux/pci-pwrctl.h index 45e9cfe740e4..0d23dddf59ec 100644 --- a/include/linux/pci-pwrctl.h +++ b/include/linux/pci-pwrctl.h @@ -7,6 +7,7 @@ #define __PCI_PWRCTL_H__ #include +#include struct device; struct device_link; @@ -41,8 +42,10 @@ struct pci_pwrctl { /* Private: don't use. */ struct notifier_block nb; struct device_link *link; + struct work_struct work; }; +void pci_pwrctl_init(struct pci_pwrctl *pwrctl, struct device *dev); int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl); void pci_pwrctl_device_unset_ready(struct pci_pwrctl *pwrctl); int devm_pci_pwrctl_device_set_ready(struct device *dev, -- cgit