On Mon, Jan 22, 2024 at 12:28:49PM -0600, Bjorn Helgaas wrote: > [+cc Johan, Kai-Heng] > > On Mon, Jan 22, 2024 at 05:43:09PM +0300, Dan Carpenter wrote: > > Hello Bjorn Helgaas, > > > > The patch f93e71aea6c6: "Revert "PCI/ASPM: Remove > > pcie_aspm_pm_state_change()"" from Jan 1, 2024 (linux-next), leads to > > the following Smatch static checker warning: > > > > drivers/pci/pcie/aspm.c:1017 pcie_aspm_pm_state_change() > > warn: sleeping in atomic context > > Thanks Dan, this is probably related to the lockdep issue Johan > reported here: > https://lore.kernel.org/r/ZZu0qx2cmn7IwTyQ@xxxxxxxxxxxxxxxxxxxx This looks like a separate issue actually. > > drivers/pci/pcie/aspm.c > > 1007 void pcie_aspm_pm_state_change(struct pci_dev *pdev) > > 1008 { > > 1009 struct pcie_link_state *link = pdev->link_state; > > 1010 > > 1011 if (aspm_disabled || !link) > > 1012 return; > > 1013 /* > > 1014 * Devices changed PM state, we should recheck if latency > > 1015 * meets all functions' requirement > > 1016 */ > > --> 1017 down_read(&pci_bus_sem); > > > > This is a revert from a patch from 2022 which was before I had written > > this "sleeping in atomic" static checker thing. > > > > 1018 mutex_lock(&aspm_lock); > > 1019 pcie_update_aspm_capable(link->root); > > 1020 pcie_config_aspm_path(link); > > 1021 mutex_unlock(&aspm_lock); > > 1022 up_read(&pci_bus_sem); > > 1023 } > > > > The call trees that Smatch is complaining about are: > > > > vortex_boomerang_interrupt() <- disables preempt > > -> _vortex_interrupt() > > -> _boomerang_interrupt() > > -> vortex_error() > > -> vortex_up() > > velocity_suspend() <- disables preempt > > -> velocity_set_power_state() > > -> pci_set_power_state() > > -> pci_set_low_power_state() > > -> pcie_aspm_pm_state_change() Based on a very quick look, I don't think it has ever been valid to call pci_set_power_state() from atomic context as it for, for example, can call pci_bus_set_current_state() which also takes the bus semaphore. Johan
