1 files changed, 45 insertions, 56 deletions

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 42914e04d110..9da84b8b27d8 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -104,11 +104,10 @@ static inline void pciehp_free_irq(struct controller *ctrl)
 		free_irq(ctrl->pcie->irq, ctrl);
 }
 
-static int pcie_poll_cmd(struct controller *ctrl)
+static int pcie_poll_cmd(struct controller *ctrl, int timeout)
 {
 	struct pci_dev *pdev = ctrl_dev(ctrl);
 	u16 slot_status;
-	int timeout = 1000;
 
 	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
 	if (slot_status & PCI_EXP_SLTSTA_CC) {
@@ -129,18 +128,52 @@ static int pcie_poll_cmd(struct controller *ctrl)
 	return 0;	/* timeout */
 }
 
-static void pcie_wait_cmd(struct controller *ctrl, int poll)
+static void pcie_wait_cmd(struct controller *ctrl)
 {
 	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
-	unsigned long timeout = msecs_to_jiffies(msecs);
+	unsigned long duration = msecs_to_jiffies(msecs);
+	unsigned long cmd_timeout = ctrl->cmd_started + duration;
+	unsigned long now, timeout;
 	int rc;
 
-	if (poll)
-		rc = pcie_poll_cmd(ctrl);
+	/*
+	 * If the controller does not generate notifications for command
+	 * completions, we never need to wait between writes.
+	 */
+	if (NO_CMD_CMPL(ctrl))
+		return;
+
+	if (!ctrl->cmd_busy)
+		return;
+
+	/*
+	 * Even if the command has already timed out, we want to call
+	 * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC.
+	 */
+	now = jiffies;
+	if (time_before_eq(cmd_timeout, now))
+		timeout = 1;
 	else
+		timeout = cmd_timeout - now;
+
+	if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
+	    ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
 		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
+	else
+		rc = pcie_poll_cmd(ctrl, timeout);
+
+	/*
+	 * Controllers with errata like Intel CF118 don't generate
+	 * completion notifications unless the power/indicator/interlock
+	 * control bits are changed.  On such controllers, we'll emit this
+	 * timeout message when we wait for completion of commands that
+	 * don't change those bits, e.g., commands that merely enable
+	 * interrupts.
+	 */
 	if (!rc)
-		ctrl_dbg(ctrl, "Command not completed in 1000 msec\n");
+		ctrl_info(ctrl, "Timeout on hotplug command %#010x (issued %u msec ago)\n",
+			  ctrl->slot_ctrl,
+			  jiffies_to_msecs(now - ctrl->cmd_started));
 }
 
 /**
@@ -152,34 +185,12 @@ static void pcie_wait_cmd(struct controller *ctrl, int poll)
 static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
 {
 	struct pci_dev *pdev = ctrl_dev(ctrl);
-	u16 slot_status;
 	u16 slot_ctrl;
 
 	mutex_lock(&ctrl->ctrl_lock);
 
-	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
-	if (slot_status & PCI_EXP_SLTSTA_CC) {
-		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
-					   PCI_EXP_SLTSTA_CC);
-		if (!ctrl->no_cmd_complete) {
-			/*
-			 * After 1 sec and CMD_COMPLETED still not set, just
-			 * proceed forward to issue the next command according
-			 * to spec. Just print out the error message.
-			 */
-			ctrl_dbg(ctrl, "CMD_COMPLETED not clear after 1 sec\n");
-		} else if (!NO_CMD_CMPL(ctrl)) {
-			/*
-			 * This controller seems to notify of command completed
-			 * event even though it supports none of power
-			 * controller, attention led, power led and EMI.
-			 */
-			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Need to wait for command completed event\n");
-			ctrl->no_cmd_complete = 0;
-		} else {
-			ctrl_dbg(ctrl, "Unexpected CMD_COMPLETED. Maybe the controller is broken\n");
-		}
-	}
+	/* Wait for any previous command that might still be in progress */
+	pcie_wait_cmd(ctrl);
 
 	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
 	slot_ctrl &= ~mask;
@@ -187,22 +198,9 @@ static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
 	ctrl->cmd_busy = 1;
 	smp_mb();
 	pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
+	ctrl->cmd_started = jiffies;
+	ctrl->slot_ctrl = slot_ctrl;
 
-	/*
-	 * Wait for command completion.
-	 */
-	if (!ctrl->no_cmd_complete) {
-		int poll = 0;
-		/*
-		 * if hotplug interrupt is not enabled or command
-		 * completed interrupt is not enabled, we need to poll
-		 * command completed event.
-		 */
-		if (!(slot_ctrl & PCI_EXP_SLTCTL_HPIE) ||
-		    !(slot_ctrl & PCI_EXP_SLTCTL_CCIE))
-			poll = 1;
-		pcie_wait_cmd(ctrl, poll);
-	}
 	mutex_unlock(&ctrl->ctrl_lock);
 }
 
@@ -773,15 +771,6 @@ struct controller *pcie_init(struct pcie_device *dev)
 	mutex_init(&ctrl->ctrl_lock);
 	init_waitqueue_head(&ctrl->queue);
 	dbg_ctrl(ctrl);
-	/*
-	 * Controller doesn't notify of command completion if the "No
-	 * Command Completed Support" bit is set in Slot Capability
-	 * register or the controller supports none of power
-	 * controller, attention led, power led and EMI.
-	 */
-	if (NO_CMD_CMPL(ctrl) ||
-	    !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl)))
-		ctrl->no_cmd_complete = 1;
 
 	/* Check if Data Link Layer Link Active Reporting is implemented */
 	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
@@ -794,7 +783,7 @@ struct controller *pcie_init(struct pcie_device *dev)
 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
 		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
 		PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
-		PCI_EXP_SLTSTA_CC);
+		PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
 
 	/* Disable software notification */
 	pcie_disable_notification(ctrl);