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authorKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>2009-02-03 01:06:16 -0500
committerJesse Barnes <jbarnes@hobbes.lan>2009-03-19 22:29:29 -0400
commit99f0169c17f334a11b0ace91188501c612f3e1e6 (patch)
tree1dab8a0f010f62611945063abcd6f988dca7bf3e /drivers/pci/hotplug/pciehp_hpc.c
parent81b840cd27e3ee9af67b6e05a4847868f74fce69 (diff)
PCI: pciehp: enable software notification on empty slots
Current pciehp disables software notification of adapter presence changed event and MRL changed event when slot is turned off. Because of this, there is no way to detect those events on empty slots in the current pciehp implementation. According to the past discussion(*), this behavior was introduced to prevent endless loop that could happen if pcie_isr() runs after power fault is detected on a certain platform whose stickey power-fault bit remains on till the slot is powered on again. (*) http://sourceforge.net/mailarchive/message.php?msg_id=20051130135409.A14918%40unix-os.sc.intel.com I think this endless loop can be avoided using one bit flag that indicates power fault had been detected, instead of disabling software notification of adapter present changed event and MRL changed event. With this patch, we can enable software notification mechanism of presence changed and MRL changed event on the empty slots again. Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/hotplug/pciehp_hpc.c')
-rw-r--r--drivers/pci/hotplug/pciehp_hpc.c31
1 files changed, 11 insertions, 20 deletions
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index c1a312f24060..07bd32151146 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -548,23 +548,21 @@ static int hpc_power_on_slot(struct slot * slot)
548 548
549 slot_cmd = POWER_ON; 549 slot_cmd = POWER_ON;
550 cmd_mask = PCI_EXP_SLTCTL_PCC; 550 cmd_mask = PCI_EXP_SLTCTL_PCC;
551 /* Enable detection that we turned off at slot power-off time */
552 if (!pciehp_poll_mode) { 551 if (!pciehp_poll_mode) {
553 slot_cmd |= (PCI_EXP_SLTCTL_PFDE | PCI_EXP_SLTCTL_MRLSCE | 552 /* Enable power fault detection turned off at power off time */
554 PCI_EXP_SLTCTL_PDCE); 553 slot_cmd |= PCI_EXP_SLTCTL_PFDE;
555 cmd_mask |= (PCI_EXP_SLTCTL_PFDE | PCI_EXP_SLTCTL_MRLSCE | 554 cmd_mask |= PCI_EXP_SLTCTL_PFDE;
556 PCI_EXP_SLTCTL_PDCE);
557 } 555 }
558 556
559 retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask); 557 retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
560
561 if (retval) { 558 if (retval) {
562 ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd); 559 ctrl_err(ctrl, "Write %x command failed!\n", slot_cmd);
563 return -1; 560 return retval;
564 } 561 }
565 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", 562 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
566 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd); 563 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
567 564
565 ctrl->power_fault_detected = 0;
568 return retval; 566 return retval;
569} 567}
570 568
@@ -621,18 +619,10 @@ static int hpc_power_off_slot(struct slot * slot)
621 619
622 slot_cmd = POWER_OFF; 620 slot_cmd = POWER_OFF;
623 cmd_mask = PCI_EXP_SLTCTL_PCC; 621 cmd_mask = PCI_EXP_SLTCTL_PCC;
624 /*
625 * If we get MRL or presence detect interrupts now, the isr
626 * will notice the sticky power-fault bit too and issue power
627 * indicator change commands. This will lead to an endless loop
628 * of command completions, since the power-fault bit remains on
629 * till the slot is powered on again.
630 */
631 if (!pciehp_poll_mode) { 622 if (!pciehp_poll_mode) {
632 slot_cmd &= ~(PCI_EXP_SLTCTL_PFDE | PCI_EXP_SLTCTL_MRLSCE | 623 /* Disable power fault detection */
633 PCI_EXP_SLTCTL_PDCE); 624 slot_cmd &= ~PCI_EXP_SLTCTL_PFDE;
634 cmd_mask |= (PCI_EXP_SLTCTL_PFDE | PCI_EXP_SLTCTL_MRLSCE | 625 cmd_mask |= PCI_EXP_SLTCTL_PFDE;
635 PCI_EXP_SLTCTL_PDCE);
636 } 626 }
637 627
638 retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask); 628 retval = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
@@ -710,9 +700,10 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
710 pciehp_handle_presence_change(p_slot); 700 pciehp_handle_presence_change(p_slot);
711 701
712 /* Check Power Fault Detected */ 702 /* Check Power Fault Detected */
713 if (intr_loc & PCI_EXP_SLTSTA_PFD) 703 if ((intr_loc & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
704 ctrl->power_fault_detected = 1;
714 pciehp_handle_power_fault(p_slot); 705 pciehp_handle_power_fault(p_slot);
715 706 }
716 return IRQ_HANDLED; 707 return IRQ_HANDLED;
717} 708}
718 709