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Commit c7ab337f authored by Thomas Schaefer's avatar Thomas Schaefer Committed by Greg Kroah-Hartman
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[PATCH] pciehp: handle sticky power-fault status 



This patch disables power fault, MRL sensor and presence detection
interrupts when a PCIe slot is powered-off and enables those
interrupts when it is powered-on again. This is necessary to prevent
the associated events from causing an endless cycle of interrupts
due to the power-fault bit, which stays set till power is restored
to the slot.

Signed-off-by: default avatarThomas Schaefer <thomas.schaefer@kontron.com>
Signed-off-by: default avatarRajesh Shah <rajesh.shah@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 9d265124

drivers/pci/hotplug/pciehp_hpc.c

+17 −2
Original line number Diff line number Diff line
@@ -787,8 +787,13 @@ static int hpc_power_on_slot(struct slot * slot) 


	slot_cmd = (slot_ctrl & ~PWR_CTRL) | POWER_ON;



	/* Enable detection that we turned off at slot power-off time */

	if (!pciehp_poll_mode)

		slot_cmd = slot_cmd | HP_INTR_ENABLE; 

		slot_cmd = slot_cmd |

		           PWR_FAULT_DETECT_ENABLE |

		           MRL_DETECT_ENABLE |

		           PRSN_DETECT_ENABLE |

		           HP_INTR_ENABLE;



	retval = pcie_write_cmd(slot, slot_cmd);
@@ -833,8 +838,18 @@ static int hpc_power_off_slot(struct slot * slot) 


	slot_cmd = (slot_ctrl & ~PWR_CTRL) | POWER_OFF;



	/*

	 * If we get MRL or presence detect interrupts now, the isr

	 * will notice the sticky power-fault bit too and issue power

	 * indicator change commands. This will lead to an endless loop

	 * of command completions, since the power-fault bit remains on

	 * till the slot is powered on again.

	 */

	if (!pciehp_poll_mode)

		slot_cmd = slot_cmd | HP_INTR_ENABLE; 

		slot_cmd = (slot_cmd &

		            ~PWR_FAULT_DETECT_ENABLE &

		            ~MRL_DETECT_ENABLE &

		            ~PRSN_DETECT_ENABLE) | HP_INTR_ENABLE;



	retval = pcie_write_cmd(slot, slot_cmd);