PCI: pciehp: Add reset_slot() method
PCIe hotplug has a bus per slot, so we can just use a normal
secondary bus reset. However, if a slot supports surprise removal,
a bus reset can be seen as a presence detection change triggering
a hot-remove followed by a hot-add. Disable presence detection from
triggering an interrupt or being polled around the bus reset.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index b225573..51f56ef 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -749,6 +749,37 @@
ctrl_warn(ctrl, "Cannot disable software notification\n");
}
+/*
+ * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
+ * bus reset of the bridge, but if the slot supports surprise removal we need
+ * to disable presence detection around the bus reset and clear any spurious
+ * events after.
+ */
+int pciehp_reset_slot(struct slot *slot, int probe)
+{
+ struct controller *ctrl = slot->ctrl;
+
+ if (probe)
+ return 0;
+
+ if (HP_SUPR_RM(ctrl)) {
+ pcie_write_cmd(ctrl, 0, PCI_EXP_SLTCTL_PDCE);
+ if (pciehp_poll_mode)
+ del_timer_sync(&ctrl->poll_timer);
+ }
+
+ pci_reset_bridge_secondary_bus(ctrl->pcie->port);
+
+ if (HP_SUPR_RM(ctrl)) {
+ pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_PDC);
+ pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PDCE, PCI_EXP_SLTCTL_PDCE);
+ if (pciehp_poll_mode)
+ int_poll_timeout(ctrl->poll_timer.data);
+ }
+
+ return 0;
+}
+
int pcie_init_notification(struct controller *ctrl)
{
if (pciehp_request_irq(ctrl))