--- zzzz-none-000/linux-3.10.107/drivers/pci/hotplug/pciehp_ctrl.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/pci/hotplug/pciehp_ctrl.c	2021-02-04 17:41:59.000000000 +0000
@@ -37,132 +37,32 @@
 
 static void interrupt_event_handler(struct work_struct *work);
 
-static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
+void pciehp_queue_interrupt_event(struct slot *p_slot, u32 event_type)
 {
 	struct event_info *info;
 
 	info = kmalloc(sizeof(*info), GFP_ATOMIC);
-	if (!info)
-		return -ENOMEM;
+	if (!info) {
+		ctrl_err(p_slot->ctrl, "dropped event %d (ENOMEM)\n", event_type);
+		return;
+	}
 
+	INIT_WORK(&info->work, interrupt_event_handler);
 	info->event_type = event_type;
 	info->p_slot = p_slot;
-	INIT_WORK(&info->work, interrupt_event_handler);
-
 	queue_work(p_slot->wq, &info->work);
-
-	return 0;
-}
-
-u8 pciehp_handle_attention_button(struct slot *p_slot)
-{
-	u32 event_type;
-	struct controller *ctrl = p_slot->ctrl;
-
-	/* Attention Button Change */
-	ctrl_dbg(ctrl, "Attention button interrupt received\n");
-
-	/*
-	 *  Button pressed - See if need to TAKE ACTION!!!
-	 */
-	ctrl_info(ctrl, "Button pressed on Slot(%s)\n", slot_name(p_slot));
-	event_type = INT_BUTTON_PRESS;
-
-	queue_interrupt_event(p_slot, event_type);
-
-	return 0;
-}
-
-u8 pciehp_handle_switch_change(struct slot *p_slot)
-{
-	u8 getstatus;
-	u32 event_type;
-	struct controller *ctrl = p_slot->ctrl;
-
-	/* Switch Change */
-	ctrl_dbg(ctrl, "Switch interrupt received\n");
-
-	pciehp_get_latch_status(p_slot, &getstatus);
-	if (getstatus) {
-		/*
-		 * Switch opened
-		 */
-		ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
-		event_type = INT_SWITCH_OPEN;
-	} else {
-		/*
-		 *  Switch closed
-		 */
-		ctrl_info(ctrl, "Latch close on Slot(%s)\n", slot_name(p_slot));
-		event_type = INT_SWITCH_CLOSE;
-	}
-
-	queue_interrupt_event(p_slot, event_type);
-
-	return 1;
-}
-
-u8 pciehp_handle_presence_change(struct slot *p_slot)
-{
-	u32 event_type;
-	u8 presence_save;
-	struct controller *ctrl = p_slot->ctrl;
-
-	/* Presence Change */
-	ctrl_dbg(ctrl, "Presence/Notify input change\n");
-
-	/* Switch is open, assume a presence change
-	 * Save the presence state
-	 */
-	pciehp_get_adapter_status(p_slot, &presence_save);
-	if (presence_save) {
-		/*
-		 * Card Present
-		 */
-		ctrl_info(ctrl, "Card present on Slot(%s)\n", slot_name(p_slot));
-		event_type = INT_PRESENCE_ON;
-	} else {
-		/*
-		 * Not Present
-		 */
-		ctrl_info(ctrl, "Card not present on Slot(%s)\n",
-			  slot_name(p_slot));
-		event_type = INT_PRESENCE_OFF;
-	}
-
-	queue_interrupt_event(p_slot, event_type);
-
-	return 1;
-}
-
-u8 pciehp_handle_power_fault(struct slot *p_slot)
-{
-	u32 event_type;
-	struct controller *ctrl = p_slot->ctrl;
-
-	/* power fault */
-	ctrl_dbg(ctrl, "Power fault interrupt received\n");
-	ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(p_slot));
-	event_type = INT_POWER_FAULT;
-	ctrl_info(ctrl, "Power fault bit %x set\n", 0);
-	queue_interrupt_event(p_slot, event_type);
-
-	return 1;
 }
 
 /* The following routines constitute the bulk of the
    hotplug controller logic
  */
 
-static void set_slot_off(struct controller *ctrl, struct slot * pslot)
+static void set_slot_off(struct controller *ctrl, struct slot *pslot)
 {
 	/* turn off slot, turn on Amber LED, turn off Green LED if supported*/
 	if (POWER_CTRL(ctrl)) {
-		if (pciehp_power_off_slot(pslot)) {
-			ctrl_err(ctrl,
-				 "Issue of Slot Power Off command failed\n");
-			return;
-		}
+		pciehp_power_off_slot(pslot);
+
 		/*
 		 * After turning power off, we must wait for at least 1 second
 		 * before taking any action that relies on power having been
@@ -171,16 +71,8 @@
 		msleep(1000);
 	}
 
-	if (PWR_LED(ctrl))
-		pciehp_green_led_off(pslot);
-
-	if (ATTN_LED(ctrl)) {
-		if (pciehp_set_attention_status(pslot, 1)) {
-			ctrl_err(ctrl,
-				 "Issue of Set Attention Led command failed\n");
-			return;
-		}
-	}
+	pciehp_green_led_off(pslot);
+	pciehp_set_attention_status(pslot, 1);
 }
 
 /**
@@ -203,8 +95,7 @@
 			return retval;
 	}
 
-	if (PWR_LED(ctrl))
-		pciehp_green_led_blink(p_slot);
+	pciehp_green_led_blink(p_slot);
 
 	/* Check link training status */
 	retval = pciehp_check_link_status(ctrl);
@@ -224,12 +115,11 @@
 	if (retval) {
 		ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
 			 pci_domain_nr(parent), parent->number);
-		goto err_exit;
+		if (retval != -EEXIST)
+			goto err_exit;
 	}
 
-	if (PWR_LED(ctrl))
-		pciehp_green_led_on(p_slot);
-
+	pciehp_green_led_on(p_slot);
 	return 0;
 
 err_exit:
@@ -243,7 +133,7 @@
  */
 static int remove_board(struct slot *p_slot)
 {
-	int retval = 0;
+	int retval;
 	struct controller *ctrl = p_slot->ctrl;
 
 	retval = pciehp_unconfigure_device(p_slot);
@@ -251,13 +141,8 @@
 		return retval;
 
 	if (POWER_CTRL(ctrl)) {
-		/* power off slot */
-		retval = pciehp_power_off_slot(p_slot);
-		if (retval) {
-			ctrl_err(ctrl,
-				 "Issue of Slot Disable command failed\n");
-			return retval;
-		}
+		pciehp_power_off_slot(p_slot);
+
 		/*
 		 * After turning power off, we must wait for at least 1 second
 		 * before taking any action that relies on power having been
@@ -267,15 +152,16 @@
 	}
 
 	/* turn off Green LED */
-	if (PWR_LED(ctrl))
-		pciehp_green_led_off(p_slot);
-
+	pciehp_green_led_off(p_slot);
 	return 0;
 }
 
 struct power_work_info {
 	struct slot *p_slot;
 	struct work_struct work;
+	unsigned int req;
+#define DISABLE_REQ 0
+#define ENABLE_REQ  1
 };
 
 /**
@@ -290,62 +176,67 @@
 	struct power_work_info *info =
 		container_of(work, struct power_work_info, work);
 	struct slot *p_slot = info->p_slot;
+	int ret;
 
-	mutex_lock(&p_slot->lock);
-	switch (p_slot->state) {
-	case POWEROFF_STATE:
-		mutex_unlock(&p_slot->lock);
-		ctrl_dbg(p_slot->ctrl,
-			 "Disabling domain:bus:device=%04x:%02x:00\n",
-			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),
-			 p_slot->ctrl->pcie->port->subordinate->number);
+	switch (info->req) {
+	case DISABLE_REQ:
+		mutex_lock(&p_slot->hotplug_lock);
 		pciehp_disable_slot(p_slot);
+		mutex_unlock(&p_slot->hotplug_lock);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
-		break;
-	case POWERON_STATE:
 		mutex_unlock(&p_slot->lock);
-		if (pciehp_enable_slot(p_slot) && PWR_LED(p_slot->ctrl))
+		break;
+	case ENABLE_REQ:
+		mutex_lock(&p_slot->hotplug_lock);
+		ret = pciehp_enable_slot(p_slot);
+		mutex_unlock(&p_slot->hotplug_lock);
+		if (ret)
 			pciehp_green_led_off(p_slot);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
+		mutex_unlock(&p_slot->lock);
 		break;
 	default:
 		break;
 	}
-	mutex_unlock(&p_slot->lock);
 
 	kfree(info);
 }
 
-void pciehp_queue_pushbutton_work(struct work_struct *work)
+static void pciehp_queue_power_work(struct slot *p_slot, int req)
 {
-	struct slot *p_slot = container_of(work, struct slot, work.work);
 	struct power_work_info *info;
 
+	p_slot->state = (req == ENABLE_REQ) ? POWERON_STATE : POWEROFF_STATE;
+
 	info = kmalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {
-		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
-			 __func__);
+		ctrl_err(p_slot->ctrl, "no memory to queue %s request\n",
+			 (req == ENABLE_REQ) ? "poweron" : "poweroff");
 		return;
 	}
 	info->p_slot = p_slot;
 	INIT_WORK(&info->work, pciehp_power_thread);
+	info->req = req;
+	queue_work(p_slot->wq, &info->work);
+}
+
+void pciehp_queue_pushbutton_work(struct work_struct *work)
+{
+	struct slot *p_slot = container_of(work, struct slot, work.work);
 
 	mutex_lock(&p_slot->lock);
 	switch (p_slot->state) {
 	case BLINKINGOFF_STATE:
-		p_slot->state = POWEROFF_STATE;
+		pciehp_queue_power_work(p_slot, DISABLE_REQ);
 		break;
 	case BLINKINGON_STATE:
-		p_slot->state = POWERON_STATE;
+		pciehp_queue_power_work(p_slot, ENABLE_REQ);
 		break;
 	default:
-		kfree(info);
-		goto out;
+		break;
 	}
-	queue_work(p_slot->wq, &info->work);
- out:
 	mutex_unlock(&p_slot->lock);
 }
 
@@ -362,21 +253,16 @@
 		pciehp_get_power_status(p_slot, &getstatus);
 		if (getstatus) {
 			p_slot->state = BLINKINGOFF_STATE;
-			ctrl_info(ctrl,
-				  "PCI slot #%s - powering off due to button "
-				  "press.\n", slot_name(p_slot));
+			ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
+				  slot_name(p_slot));
 		} else {
 			p_slot->state = BLINKINGON_STATE;
-			ctrl_info(ctrl,
-				  "PCI slot #%s - powering on due to button "
-				  "press.\n", slot_name(p_slot));
+			ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
+				  slot_name(p_slot));
 		}
 		/* blink green LED and turn off amber */
-		if (PWR_LED(ctrl))
-			pciehp_green_led_blink(p_slot);
-		if (ATTN_LED(ctrl))
-			pciehp_set_attention_status(p_slot, 0);
-
+		pciehp_green_led_blink(p_slot);
+		pciehp_set_attention_status(p_slot, 0);
 		queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
 		break;
 	case BLINKINGOFF_STATE:
@@ -388,17 +274,13 @@
 		 */
 		ctrl_info(ctrl, "Button cancel on Slot(%s)\n", slot_name(p_slot));
 		cancel_delayed_work(&p_slot->work);
-		if (p_slot->state == BLINKINGOFF_STATE) {
-			if (PWR_LED(ctrl))
-				pciehp_green_led_on(p_slot);
-		} else {
-			if (PWR_LED(ctrl))
-				pciehp_green_led_off(p_slot);
-		}
-		if (ATTN_LED(ctrl))
-			pciehp_set_attention_status(p_slot, 0);
-		ctrl_info(ctrl, "PCI slot #%s - action canceled "
-			  "due to button press\n", slot_name(p_slot));
+		if (p_slot->state == BLINKINGOFF_STATE)
+			pciehp_green_led_on(p_slot);
+		else
+			pciehp_green_led_off(p_slot);
+		pciehp_set_attention_status(p_slot, 0);
+		ctrl_info(ctrl, "PCI slot #%s - action canceled due to button press\n",
+			  slot_name(p_slot));
 		p_slot->state = STATIC_STATE;
 		break;
 	case POWEROFF_STATE:
@@ -411,7 +293,7 @@
 		ctrl_info(ctrl, "Button ignore on Slot(%s)\n", slot_name(p_slot));
 		break;
 	default:
-		ctrl_warn(ctrl, "Not a valid state\n");
+		ctrl_warn(ctrl, "ignoring invalid state %#x\n", p_slot->state);
 		break;
 	}
 }
@@ -422,24 +304,59 @@
 static void handle_surprise_event(struct slot *p_slot)
 {
 	u8 getstatus;
-	struct power_work_info *info;
-
-	info = kmalloc(sizeof(*info), GFP_KERNEL);
-	if (!info) {
-		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
-			 __func__);
-		return;
-	}
-	info->p_slot = p_slot;
-	INIT_WORK(&info->work, pciehp_power_thread);
 
 	pciehp_get_adapter_status(p_slot, &getstatus);
 	if (!getstatus)
-		p_slot->state = POWEROFF_STATE;
+		pciehp_queue_power_work(p_slot, DISABLE_REQ);
 	else
-		p_slot->state = POWERON_STATE;
+		pciehp_queue_power_work(p_slot, ENABLE_REQ);
+}
 
-	queue_work(p_slot->wq, &info->work);
+/*
+ * Note: This function must be called with slot->lock held
+ */
+static void handle_link_event(struct slot *p_slot, u32 event)
+{
+	struct controller *ctrl = p_slot->ctrl;
+
+	switch (p_slot->state) {
+	case BLINKINGON_STATE:
+	case BLINKINGOFF_STATE:
+		cancel_delayed_work(&p_slot->work);
+		/* Fall through */
+	case STATIC_STATE:
+		pciehp_queue_power_work(p_slot, event == INT_LINK_UP ?
+					ENABLE_REQ : DISABLE_REQ);
+		break;
+	case POWERON_STATE:
+		if (event == INT_LINK_UP) {
+			ctrl_info(ctrl,
+				  "Link Up event ignored on slot(%s): already powering on\n",
+				  slot_name(p_slot));
+		} else {
+			ctrl_info(ctrl,
+				  "Link Down event queued on slot(%s): currently getting powered on\n",
+				  slot_name(p_slot));
+			pciehp_queue_power_work(p_slot, DISABLE_REQ);
+		}
+		break;
+	case POWEROFF_STATE:
+		if (event == INT_LINK_UP) {
+			ctrl_info(ctrl,
+				  "Link Up event queued on slot(%s): currently getting powered off\n",
+				  slot_name(p_slot));
+			pciehp_queue_power_work(p_slot, ENABLE_REQ);
+		} else {
+			ctrl_info(ctrl,
+				  "Link Down event ignored on slot(%s): already powering off\n",
+				  slot_name(p_slot));
+		}
+		break;
+	default:
+		ctrl_err(ctrl, "ignoring invalid state %#x on slot(%s)\n",
+			 p_slot->state, slot_name(p_slot));
+		break;
+	}
 }
 
 static void interrupt_event_handler(struct work_struct *work)
@@ -456,18 +373,23 @@
 	case INT_POWER_FAULT:
 		if (!POWER_CTRL(ctrl))
 			break;
-		if (ATTN_LED(ctrl))
-			pciehp_set_attention_status(p_slot, 1);
-		if (PWR_LED(ctrl))
-			pciehp_green_led_off(p_slot);
+		pciehp_set_attention_status(p_slot, 1);
+		pciehp_green_led_off(p_slot);
 		break;
 	case INT_PRESENCE_ON:
+		handle_surprise_event(p_slot);
+		break;
 	case INT_PRESENCE_OFF:
-		if (!HP_SUPR_RM(ctrl))
-			break;
-		ctrl_dbg(ctrl, "Surprise Removal\n");
+		/*
+		 * Regardless of surprise capability, we need to
+		 * definitely remove a card that has been pulled out!
+		 */
 		handle_surprise_event(p_slot);
 		break;
+	case INT_LINK_UP:
+	case INT_LINK_DOWN:
+		handle_link_event(p_slot, info->event_type);
+		break;
 	default:
 		break;
 	}
@@ -476,20 +398,23 @@
 	kfree(info);
 }
 
+/*
+ * Note: This function must be called with slot->hotplug_lock held
+ */
 int pciehp_enable_slot(struct slot *p_slot)
 {
 	u8 getstatus = 0;
 	int rc;
 	struct controller *ctrl = p_slot->ctrl;
 
-	rc = pciehp_get_adapter_status(p_slot, &getstatus);
-	if (rc || !getstatus) {
+	pciehp_get_adapter_status(p_slot, &getstatus);
+	if (!getstatus) {
 		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
 		return -ENODEV;
 	}
 	if (MRL_SENS(p_slot->ctrl)) {
-		rc = pciehp_get_latch_status(p_slot, &getstatus);
-		if (rc || getstatus) {
+		pciehp_get_latch_status(p_slot, &getstatus);
+		if (getstatus) {
 			ctrl_info(ctrl, "Latch open on slot(%s)\n",
 				  slot_name(p_slot));
 			return -ENODEV;
@@ -497,8 +422,8 @@
 	}
 
 	if (POWER_CTRL(p_slot->ctrl)) {
-		rc = pciehp_get_power_status(p_slot, &getstatus);
-		if (rc || getstatus) {
+		pciehp_get_power_status(p_slot, &getstatus);
+		if (getstatus) {
 			ctrl_info(ctrl, "Already enabled on slot(%s)\n",
 				  slot_name(p_slot));
 			return -EINVAL;
@@ -508,43 +433,26 @@
 	pciehp_get_latch_status(p_slot, &getstatus);
 
 	rc = board_added(p_slot);
-	if (rc) {
+	if (rc)
 		pciehp_get_latch_status(p_slot, &getstatus);
-	}
+
 	return rc;
 }
 
-
+/*
+ * Note: This function must be called with slot->hotplug_lock held
+ */
 int pciehp_disable_slot(struct slot *p_slot)
 {
 	u8 getstatus = 0;
-	int ret = 0;
 	struct controller *ctrl = p_slot->ctrl;
 
 	if (!p_slot->ctrl)
 		return 1;
 
-	if (!HP_SUPR_RM(p_slot->ctrl)) {
-		ret = pciehp_get_adapter_status(p_slot, &getstatus);
-		if (ret || !getstatus) {
-			ctrl_info(ctrl, "No adapter on slot(%s)\n",
-				  slot_name(p_slot));
-			return -ENODEV;
-		}
-	}
-
-	if (MRL_SENS(p_slot->ctrl)) {
-		ret = pciehp_get_latch_status(p_slot, &getstatus);
-		if (ret || getstatus) {
-			ctrl_info(ctrl, "Latch open on slot(%s)\n",
-				  slot_name(p_slot));
-			return -ENODEV;
-		}
-	}
-
 	if (POWER_CTRL(p_slot->ctrl)) {
-		ret = pciehp_get_power_status(p_slot, &getstatus);
-		if (ret || !getstatus) {
+		pciehp_get_power_status(p_slot, &getstatus);
+		if (!getstatus) {
 			ctrl_info(ctrl, "Already disabled on slot(%s)\n",
 				  slot_name(p_slot));
 			return -EINVAL;
@@ -566,7 +474,9 @@
 	case STATIC_STATE:
 		p_slot->state = POWERON_STATE;
 		mutex_unlock(&p_slot->lock);
+		mutex_lock(&p_slot->hotplug_lock);
 		retval = pciehp_enable_slot(p_slot);
+		mutex_unlock(&p_slot->hotplug_lock);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
 		break;
@@ -580,8 +490,8 @@
 			  slot_name(p_slot));
 		break;
 	default:
-		ctrl_err(ctrl, "Not a valid state on slot %s\n",
-			 slot_name(p_slot));
+		ctrl_err(ctrl, "invalid state %#x on slot %s\n",
+			 p_slot->state, slot_name(p_slot));
 		break;
 	}
 	mutex_unlock(&p_slot->lock);
@@ -615,8 +525,8 @@
 			  slot_name(p_slot));
 		break;
 	default:
-		ctrl_err(ctrl, "Not a valid state on slot %s\n",
-			 slot_name(p_slot));
+		ctrl_err(ctrl, "invalid state %#x on slot %s\n",
+			 p_slot->state, slot_name(p_slot));
 		break;
 	}
 	mutex_unlock(&p_slot->lock);