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PCI: pciehp: Add reset_slot() method

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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>
This commit is contained in:
Alex Williamson
2013-08-08 14:09:37 -06:00
committed by Bjorn Helgaas
parent 5c32b35b00
commit 2e35afaefe
3 changed files with 44 additions and 0 deletions
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31
drivers/pci/hotplug/pciehp_hpc.c
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@@ -749,6 +749,37 @@ static void pcie_disable_notification(struct controller *ctrl)
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))