PCI: pciehp: Make pcie_wait_cmd() self-contained

pcie_wait_cmd() waits for the controller to finish a hotplug command.  Move
the associated logic (to determine whether waiting is required and whether
we're using interrupts or polling) from pcie_write_cmd() to
pcie_wait_cmd().

No functional change.

Tested-by: Rajat Jain <rajatxjain@gmail.com>	(IDT 807a controller)
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>

drivers/pci/hotplug/pciehp.h

@@ -92,6 +92,7 @@ struct controller {
 	struct slot *slot;
 	wait_queue_head_t queue;	/* sleep & wake process */
 	u32 slot_cap;
+	u32 slot_ctrl;
 	struct timer_list poll_timer;
 	unsigned int cmd_busy:1;
 	unsigned int no_cmd_complete:1;

drivers/pci/hotplug/pciehp_hpc.c

@@ -129,16 +129,27 @@ 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);
 	int rc;
 
-	if (poll)
-		rc = pcie_poll_cmd(ctrl);
-	else
+	/*
+	 * If the controller does not generate notifications for command
+	 * completions, we never need to wait between writes.
+	 */
+	if (ctrl->no_cmd_complete)
+		return;
+
+	if (!ctrl->cmd_busy)
+		return;
+
+	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);
 	if (!rc)
 		ctrl_dbg(ctrl, "Command not completed in 1000 msec\n");
 }
@@ -187,22 +198,12 @@ 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->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);
-	}
+	pcie_wait_cmd(ctrl);
 	mutex_unlock(&ctrl->ctrl_lock);
 }