diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2024-08-23 11:33:23 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2024-09-03 17:11:05 -0500 |
| commit | 8f62819aaace77dd85037ae766eb767f8c4417ce (patch) | |
| tree | fa176d1760bf08e148e38ae41632fc8a67700859 | |
| parent | f1536585588ba630c533b6ffbca8ad8424aa5c39 (diff) | |
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 <konradybcio@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
| -rw-r--r-- | drivers/pci/pwrctl/core.c | 26 | ||||
| -rw-r--r-- | drivers/pci/pwrctl/pci-pwrctl-pwrseq.c | 2 | ||||
| -rw-r--r-- | 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 <linux/notifier.h> +#include <linux/workqueue.h> 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, |