From pcihpd-discuss-admin@lists.sourceforge.net Thu Nov 10 11:49:16 2005 From: Rajesh Shah To: , Cc: Message-ID: <20051110114536.B18893@unix-os.sc.intel.com> Content-Disposition: inline Subject: PCI Express Hotplug: clear sticky power-fault bit Date: Thu, 10 Nov 2005 11:45:36 -0800 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: Rajesh Shah Signed-off-by: Greg Kroah-Hartman --- drivers/pci/hotplug/pciehp.h | 1 - drivers/pci/hotplug/pciehp_ctrl.c | 15 ++------------- drivers/pci/hotplug/pciehp_hpc.c | 10 +++++++++- 3 files changed, 11 insertions(+), 15 deletions(-) --- gregkh-2.6.orig/drivers/pci/hotplug/pciehp.h +++ gregkh-2.6/drivers/pci/hotplug/pciehp.h @@ -59,7 +59,6 @@ struct slot { struct slot *next; u8 bus; u8 device; - u16 status; u32 number; u8 state; struct timer_list task_event; --- gregkh-2.6.orig/drivers/pci/hotplug/pciehp_ctrl.c +++ gregkh-2.6/drivers/pci/hotplug/pciehp_ctrl.c @@ -207,7 +207,6 @@ u8 pciehp_handle_power_fault(u8 hp_slot, * 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, */ 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_sl 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_sl 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_s 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); --- gregkh-2.6.orig/drivers/pci/hotplug/pciehp_hpc.c +++ gregkh-2.6/drivers/pci/hotplug/pciehp_hpc.c @@ -750,7 +750,7 @@ static int hpc_power_on_slot(struct 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 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) {