From c4eed62a214330908eec11b0dc170d34fa50b412 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Thu, 20 Sep 2018 10:27:11 -0600 Subject: PCI/ERR: Use slot reset if available The secondary bus reset may have link side effects that a hotplug capable port may incorrectly react to. Use the slot specific reset for hotplug ports, fixing the undesirable link down-up handling during error recovering. Signed-off-by: Keith Busch [bhelgaas: fold in https://lore.kernel.org/linux-pci/20180926152326.14821-1-keith.busch@intel.com for issue reported by Stephen Rothwell ] Signed-off-by: Bjorn Helgaas Reviewed-by: Sinan Kaya --- drivers/pci/pci.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d6bb56fbee6d..6916af269b19 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -35,6 +35,8 @@ #include #include "pci.h" +DEFINE_MUTEX(pci_slot_mutex); + const char *pci_power_names[] = { "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown", }; @@ -5155,6 +5157,41 @@ static int pci_bus_reset(struct pci_bus *bus, int probe) return ret; } +/** + * pci_bus_error_reset - reset the bridge's subordinate bus + * @bridge: The parent device that connects to the bus to reset + * + * This function will first try to reset the slots on this bus if the method is + * available. If slot reset fails or is not available, this will fall back to a + * secondary bus reset. + */ +int pci_bus_error_reset(struct pci_dev *bridge) +{ + struct pci_bus *bus = bridge->subordinate; + struct pci_slot *slot; + + if (!bus) + return -ENOTTY; + + mutex_lock(&pci_slot_mutex); + if (list_empty(&bus->slots)) + goto bus_reset; + + list_for_each_entry(slot, &bus->slots, list) + if (pci_probe_reset_slot(slot)) + goto bus_reset; + + list_for_each_entry(slot, &bus->slots, list) + if (pci_slot_reset(slot, 0)) + goto bus_reset; + + mutex_unlock(&pci_slot_mutex); + return 0; +bus_reset: + mutex_unlock(&pci_slot_mutex); + return pci_bus_reset(bridge->subordinate, 0); +} + /** * pci_probe_reset_bus - probe whether a PCI bus can be reset * @bus: PCI bus to probe -- cgit v1.2.1