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Commit 2e35afaefe64946caaecfacaf7fb568e46185e88

Authored by Alex Williamson
Committed by Bjorn Helgaas
1 parent 5c32b35b00
Exists in smarc-imx_3.14.28_1.0.0_ga and in 1 other branch imx_3.14.28_1.0.0_ga

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>

Showing 3 changed files with 44 additions and 0 deletions Side-by-side Diff

drivers/pci/hotplug/pciehp.h
Diff comments   View file @ 2e35afa
... ... @@ -155,6 +155,7 @@
155 155 void pciehp_green_led_blink(struct slot *slot);
156 156 int pciehp_check_link_status(struct controller *ctrl);
157 157 void pciehp_release_ctrl(struct controller *ctrl);
  158 +int pciehp_reset_slot(struct slot *slot, int probe);
158 159  
159 160 static inline const char *slot_name(struct slot *slot)
160 161 {
drivers/pci/hotplug/pciehp_core.c
Diff comments   View file @ 2e35afa
... ... @@ -69,6 +69,7 @@
69 69 static int get_attention_status (struct hotplug_slot *slot, u8 *value);
70 70 static int get_latch_status (struct hotplug_slot *slot, u8 *value);
71 71 static int get_adapter_status (struct hotplug_slot *slot, u8 *value);
  72 +static int reset_slot (struct hotplug_slot *slot, int probe);
72 73  
73 74 /**
74 75 * release_slot - free up the memory used by a slot
... ... @@ -111,6 +112,7 @@
111 112 ops->disable_slot = disable_slot;
112 113 ops->get_power_status = get_power_status;
113 114 ops->get_adapter_status = get_adapter_status;
  115 + ops->reset_slot = reset_slot;
114 116 if (MRL_SENS(ctrl))
115 117 ops->get_latch_status = get_latch_status;
116 118 if (ATTN_LED(ctrl)) {
... ... @@ -221,6 +223,16 @@
221 223 __func__, slot_name(slot));
222 224  
223 225 return pciehp_get_adapter_status(slot, value);
  226 +}
  227 +
  228 +static int reset_slot(struct hotplug_slot *hotplug_slot, int probe)
  229 +{
  230 + struct slot *slot = hotplug_slot->private;
  231 +
  232 + ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
  233 + __func__, slot_name(slot));
  234 +
  235 + return pciehp_reset_slot(slot, probe);
224 236 }
225 237  
226 238 static int pciehp_probe(struct pcie_device *dev)
drivers/pci/hotplug/pciehp_hpc.c
Diff comments   View file @ 2e35afa
... ... @@ -749,6 +749,37 @@
749 749 ctrl_warn(ctrl, "Cannot disable software notification\n");
750 750 }
751 751  
  752 +/*
  753 + * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
  754 + * bus reset of the bridge, but if the slot supports surprise removal we need
  755 + * to disable presence detection around the bus reset and clear any spurious
  756 + * events after.
  757 + */
  758 +int pciehp_reset_slot(struct slot *slot, int probe)
  759 +{
  760 + struct controller *ctrl = slot->ctrl;
  761 +
  762 + if (probe)
  763 + return 0;
  764 +
  765 + if (HP_SUPR_RM(ctrl)) {
  766 + pcie_write_cmd(ctrl, 0, PCI_EXP_SLTCTL_PDCE);
  767 + if (pciehp_poll_mode)
  768 + del_timer_sync(&ctrl->poll_timer);
  769 + }
  770 +
  771 + pci_reset_bridge_secondary_bus(ctrl->pcie->port);
  772 +
  773 + if (HP_SUPR_RM(ctrl)) {
  774 + pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_PDC);
  775 + pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PDCE, PCI_EXP_SLTCTL_PDCE);
  776 + if (pciehp_poll_mode)
  777 + int_poll_timeout(ctrl->poll_timer.data);
  778 + }
  779 +
  780 + return 0;
  781 +}
  782 +
752 783 int pcie_init_notification(struct controller *ctrl)
753 784 {
754 785 if (pciehp_request_irq(ctrl))