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Commit 5a49f203 authored by Rajesh Shah's avatar Rajesh Shah Committed by Linus Torvalds
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[PATCH] PCI Express Hotplug: clear sticky power-fault bit 



Per the PCI Express spec, the power-fault-detected bit in the
slot status register can be set anytime hardware detects a power
fault, regardless of whether the slot has a device populated in
it or not. This bit is sticky and must be explicitly cleared.
This patch is needed to allow hot-add after such a power fault
has been detected.

Signed-off-by: default avatarRajesh Shah <rajesh.shah@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent dcb89074

drivers/pci/hotplug/pciehp.h

+0 −1
Original line number Diff line number Diff line
@@ -59,7 +59,6 @@ struct slot { 
	struct slot *next;

	u8 bus;

	u8 device;

	u16 status;

	u32 number;

	u8 state;

	struct timer_list task_event;

drivers/pci/hotplug/pciehp_ctrl.c

+2 −13
Original line number Diff line number Diff line
@@ -207,7 +207,6 @@ u8 pciehp_handle_power_fault(u8 hp_slot, void *inst_id) 
		 * power fault Cleared

		 */

		info("Power fault cleared on Slot(%d)\n", ctrl->first_slot + hp_slot);

		p_slot->status = 0x00;

		taskInfo->event_type = INT_POWER_FAULT_CLEAR;

	} else {

		/*
@@ -215,8 +214,6 @@ u8 pciehp_handle_power_fault(u8 hp_slot, void *inst_id) 
		 */

		info("Power fault on Slot(%d)\n", ctrl->first_slot + hp_slot);

		taskInfo->event_type = INT_POWER_FAULT;

		/* set power fault status for this board */

		p_slot->status = 0xFF;

		info("power fault bit %x set\n", hp_slot);

	}

	if (rc)
@@ -317,13 +314,10 @@ static int board_added(struct slot *p_slot) 
		return rc;

	}



	dbg("%s: slot status = %x\n", __FUNCTION__, p_slot->status);



	/* Check for a power fault */

	if (p_slot->status == 0xFF) {

		/* power fault occurred, but it was benign */

	if (p_slot->hpc_ops->query_power_fault(p_slot)) {

		dbg("%s: power fault detected\n", __FUNCTION__);

		rc = POWER_FAILURE;

		p_slot->status = 0;

		goto err_exit;

	}
@@ -334,8 +328,6 @@ static int board_added(struct slot *p_slot) 
		goto err_exit;

	}



	p_slot->status = 0;



	/*

	 * Some PCI Express root ports require fixup after hot-plug operation.

	 */
@@ -382,9 +374,6 @@ static int remove_board(struct slot *p_slot) 


	dbg("In %s, hp_slot = %d\n", __FUNCTION__, hp_slot);



	/* Change status to shutdown */

	p_slot->status = 0x01;



	/* Wait for exclusive access to hardware */

	down(&ctrl->crit_sect);

drivers/pci/hotplug/pciehp_hpc.c

+9 −1
Original line number Diff line number Diff line
@@ -750,7 +750,7 @@ static int hpc_power_on_slot(struct slot * slot) 
{

	struct php_ctlr_state_s *php_ctlr = slot->ctrl->hpc_ctlr_handle;

	u16 slot_cmd;

	u16 slot_ctrl;

	u16 slot_ctrl, slot_status;



	int retval = 0;
@@ -767,6 +767,14 @@ static int hpc_power_on_slot(struct slot * slot) 
		return -1;

	}



	/* Clear sticky power-fault bit from previous power failures */

	hp_register_read_word(php_ctlr->pci_dev,

			SLOT_STATUS(slot->ctrl->cap_base), slot_status);

	slot_status &= PWR_FAULT_DETECTED;

	if (slot_status)

		hp_register_write_word(php_ctlr->pci_dev,

			SLOT_STATUS(slot->ctrl->cap_base), slot_status);



	retval = hp_register_read_word(php_ctlr->pci_dev, SLOT_CTRL(slot->ctrl->cap_base), slot_ctrl);



	if (retval) {