diff options
| -rw-r--r-- | drivers/pci/hotplug/pnv_php.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 1304329ca6f7..5476c9e7760d 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -391,6 +391,20 @@ static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state) return 0; } +static int pcie_check_link_active(struct pci_dev *pdev) +{ + u16 lnk_status; + int ret; + + ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); + if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(lnk_status)) + return -ENODEV; + + ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA); + + return ret; +} + static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state) { struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); @@ -403,6 +417,19 @@ static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state) */ ret = pnv_pci_get_presence_state(php_slot->id, &presence); if (ret >= 0) { + if (pci_pcie_type(php_slot->pdev) == PCI_EXP_TYPE_DOWNSTREAM && + presence == OPAL_PCI_SLOT_EMPTY) { + /* + * Similar to pciehp_hpc, check whether the Link Active + * bit is set to account for broken downstream bridges + * that don't properly assert Presence Detect State, as + * was observed on the Microsemi Switchtec PM8533 PFX + * [11f8:8533]. + */ + if (pcie_check_link_active(php_slot->pdev) > 0) + presence = OPAL_PCI_SLOT_PRESENT; + } + *state = presence; ret = 0; } else { |