On Mon, May 19, 2025 at 03:58:08PM +0530, Raag Jadav wrote: > If error status is set on an AER capable device, most likely either the > device recovery is in progress or has already failed. Neither of the > cases are well suited for power state transition of the device, since > this can lead to unpredictable consequences like resume failure, or in > worst case the device is lost because of it. Leave the device in its > existing power state to avoid such issues. > > Signed-off-by: Raag Jadav <raag.jadav@xxxxxxxxx> > --- > > v2: Synchronize AER handling with PCI PM (Rafael) > v3: Move pci_aer_in_progress() to pci_set_low_power_state() (Rafael) > Elaborate "why" (Bjorn) > v4: Rely on error status instead of device status > Condense comment (Lukas) Since pci_aer_in_progress() is changed I've not included Rafael's tag with my understanding of this needing a revisit. If this was a mistake, please let me know. Denis, Mario, does this fix your issue? > More discussion on [1]. > [1] https://lore.kernel.org/all/CAJZ5v0g-aJXfVH+Uc=9eRPuW08t-6PwzdyMXsC6FZRKYJtY03Q@xxxxxxxxxxxxxx/ > > drivers/pci/pci.c | 9 +++++++++ > drivers/pci/pcie/aer.c | 13 +++++++++++++ > include/linux/aer.h | 2 ++ > 3 files changed, 24 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 4d7c9f64ea24..a20018692933 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -9,6 +9,7 @@ > */ > > #include <linux/acpi.h> > +#include <linux/aer.h> > #include <linux/kernel.h> > #include <linux/delay.h> > #include <linux/dmi.h> > @@ -1539,6 +1540,14 @@ static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state, bool > || (state == PCI_D2 && !dev->d2_support)) > return -EIO; > > + /* > + * If error status is set on an AER capable device, it is not well > + * suited for power state transition. Leave it in its existing power > + * state to avoid issues like unpredictable resume failure. > + */ > + if (pci_aer_in_progress(dev)) > + return -EIO; > + > pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); > if (PCI_POSSIBLE_ERROR(pmcsr)) { > pci_err(dev, "Unable to change power state from %s to %s, device inaccessible\n", > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c > index a1cf8c7ef628..617fbac0d38a 100644 > --- a/drivers/pci/pcie/aer.c > +++ b/drivers/pci/pcie/aer.c > @@ -237,6 +237,19 @@ int pcie_aer_is_native(struct pci_dev *dev) > } > EXPORT_SYMBOL_NS_GPL(pcie_aer_is_native, "CXL"); > > +bool pci_aer_in_progress(struct pci_dev *dev) > +{ > + int aer = dev->aer_cap; > + u32 cor, uncor; > + > + if (!pcie_aer_is_native(dev)) > + return false; > + > + pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &cor); > + pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &uncor); > + return cor || uncor; > +} > + > static int pci_enable_pcie_error_reporting(struct pci_dev *dev) > { > int rc; > diff --git a/include/linux/aer.h b/include/linux/aer.h > index 02940be66324..e6a380bb2e68 100644 > --- a/include/linux/aer.h > +++ b/include/linux/aer.h > @@ -56,12 +56,14 @@ struct aer_capability_regs { > #if defined(CONFIG_PCIEAER) > int pci_aer_clear_nonfatal_status(struct pci_dev *dev); > int pcie_aer_is_native(struct pci_dev *dev); > +bool pci_aer_in_progress(struct pci_dev *dev); > #else > static inline int pci_aer_clear_nonfatal_status(struct pci_dev *dev) > { > return -EINVAL; > } > static inline int pcie_aer_is_native(struct pci_dev *dev) { return 0; } > +static inline bool pci_aer_in_progress(struct pci_dev *dev) { return false; } > #endif > > void pci_print_aer(struct pci_dev *dev, int aer_severity, > -- > 2.34.1 >
