tegra: usb: tegra: clk_timer changes with EHCI power on/off

Disabled the power management clk_timer on EHCI power off.
Enabled the clk_timer on EHCI power on after hcd on.
This is done to avoid kernel panic during flight mode on/off.

Bug 881388

Reviewed-on: http://git-master/r/61093
(cherry picked from commit 5e36d4788f0bbfcd7c6965390f0e1a977b491a23)

Change-Id: I5f957aaa5b1c949cd395da92c83a70fdd551a6a1
Reviewed-on: http://git-master/r/65168
Reviewed-by: Lokesh Pathak <lpathak@nvidia.com>
Tested-by: Lokesh Pathak <lpathak@nvidia.com>

Rebase-Id: R7ad855dc3a9840ec4ab6b7a0bbbca24cd1ebc730

1 files changed, 72 insertions, 54 deletions

diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c
index ac13286bfe3c..a1a4c7c1093a 100644
--- a/drivers/usb/host/ehci-tegra.c
+++ b/drivers/usb/host/ehci-tegra.c
@@ -875,6 +875,58 @@ static void tegra_hsic_connection_work(struct work_struct *work)
 	return;
 }
 
+void clk_timer_callback(unsigned long data)
+{
+	struct tegra_ehci_hcd *tegra = (struct tegra_ehci_hcd*) data;
+	unsigned long flags;
+
+	if (!timer_pending(&tegra->clk_timer)) {
+		spin_lock_irqsave(&tegra->ehci->lock, flags);
+		tegra->timer_event = 1;
+		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
+		schedule_work(&tegra->clk_timer_work);
+	}
+}
+
+static void clk_timer_work_handler(struct work_struct* clk_timer_work) {
+	struct tegra_ehci_hcd *tegra = container_of(clk_timer_work,
+						struct tegra_ehci_hcd, clk_timer_work);
+	int ret;
+	unsigned long flags;
+	bool clock_enabled, timer_event;
+
+	spin_lock_irqsave(&tegra->ehci->lock, flags);
+	clock_enabled = tegra->clock_enabled;
+	timer_event = tegra->timer_event;
+	spin_unlock_irqrestore(&tegra->ehci->lock, flags);
+
+	if (timer_event) {
+		spin_lock_irqsave(&tegra->ehci->lock, flags);
+		tegra->clock_enabled = 0;
+		tegra->timer_event = 0;
+		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
+		clk_disable(tegra->emc_clk);
+		clk_disable(tegra->sclk_clk);
+		return;
+	}
+
+	if ((!clock_enabled)) {
+		ret = mod_timer(&tegra->clk_timer, jiffies + msecs_to_jiffies(2000));
+		if (ret)
+			pr_err("tegra_ehci_urb_enqueue timer modify failed \n");
+		clk_enable(tegra->emc_clk);
+		clk_enable(tegra->sclk_clk);
+		spin_lock_irqsave(&tegra->ehci->lock, flags);
+		tegra->clock_enabled = 1;
+		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
+	} else {
+		if (timer_pending(&tegra->clk_timer)) {
+			mod_timer_pending (&tegra->clk_timer, jiffies
+						+ msecs_to_jiffies(2000));
+		}
+	}
+}
+
 #ifdef CONFIG_USB_EHCI_ONOFF_FEATURE
 /* Stored ehci handle for hsic insatnce */
 struct usb_hcd *ehci_handle;
@@ -895,23 +947,41 @@ static ssize_t store_ehci_power(struct device *dev,
 	int retval;
 	struct tegra_ehci_hcd *tegra = dev_get_drvdata(dev);
 	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);
+	bool clock_enabled;
+	unsigned long flags;
 
 	if (sscanf(buf, "%d", &power_on) != 1)
 		return -EINVAL;
 
 	if (power_on == 0 && ehci_handle != NULL) {
+		del_timer_sync(&tegra->clk_timer);
+		spin_lock_irqsave(&tegra->ehci->lock, flags);
+		clock_enabled = tegra->clock_enabled;
+		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
+		if (clock_enabled) {
+			spin_lock_irqsave(&tegra->ehci->lock, flags);
+			tegra->clock_enabled = 0;
+			spin_unlock_irqrestore(&tegra->ehci->lock, flags);
+			clk_disable(tegra->emc_clk);
+			clk_disable(tegra->sclk_clk);
+		}
 		usb_remove_hcd(hcd);
 		tegra_ehci_power_down(hcd, false);
 		ehci_handle = NULL;
 	} else if (power_on == 1) {
-		if (ehci_handle)
+		if (ehci_handle) {
+			del_timer_sync(&tegra->clk_timer);
 			usb_remove_hcd(hcd);
+		}
 		tegra_ehci_power_up(hcd, false);
 		retval = usb_add_hcd(hcd, ehci_tegra_irq,
 					IRQF_DISABLED | IRQF_SHARED);
 		if (retval < 0)
 			printk(KERN_ERR "power_on error\n");
 		ehci_handle = hcd;
+		init_timer(&tegra->clk_timer);
+		tegra->clk_timer.function = clk_timer_callback;
+		tegra->clk_timer.data = (unsigned long) tegra;
 	}
 
 	return count;
@@ -934,58 +1004,6 @@ static inline void remove_ehci_sys_file(struct ehci_hcd *ehci)
 
 #endif
 
-void clk_timer_callback(unsigned long data)
-{
-	struct tegra_ehci_hcd *tegra = (struct tegra_ehci_hcd*) data;
-	unsigned long flags;
-
-	if (!timer_pending(&tegra->clk_timer)) {
-		spin_lock_irqsave(&tegra->ehci->lock, flags);
-		tegra->timer_event = 1;
-		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
-		schedule_work(&tegra->clk_timer_work);
-	}
-}
-
-static void clk_timer_work_handler(struct work_struct* clk_timer_work) {
-	struct tegra_ehci_hcd *tegra = container_of(clk_timer_work,
-						struct tegra_ehci_hcd, clk_timer_work);
-	int ret;
-	unsigned long flags;
-	bool clock_enabled, timer_event;
-
-	spin_lock_irqsave(&tegra->ehci->lock, flags);
-	clock_enabled = tegra->clock_enabled;
-	timer_event = tegra->timer_event;
-	spin_unlock_irqrestore(&tegra->ehci->lock, flags);
-
-	if (timer_event) {
-		spin_lock_irqsave(&tegra->ehci->lock, flags);
-		tegra->clock_enabled = 0;
-		tegra->timer_event = 0;
-		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
-		clk_disable(tegra->emc_clk);
-		clk_disable(tegra->sclk_clk);
-		return;
-	}
-
-	if ((!clock_enabled)) {
-		ret = mod_timer(&tegra->clk_timer, jiffies + msecs_to_jiffies(2000));
-		if (ret)
-			pr_err("tegra_ehci_urb_enqueue timer modify failed \n");
-		clk_enable(tegra->emc_clk);
-		clk_enable(tegra->sclk_clk);
-		spin_lock_irqsave(&tegra->ehci->lock, flags);
-		tegra->clock_enabled = 1;
-		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
-	} else {
-		if (timer_pending(&tegra->clk_timer)) {
-			mod_timer_pending (&tegra->clk_timer, jiffies
-						+ msecs_to_jiffies(2000));
-		}
-	}
-}
-
 static int tegra_ehci_urb_enqueue (
 	struct usb_hcd	*hcd,
 	struct urb	*urb,
@@ -1310,7 +1328,7 @@ static int tegra_ehci_remove(struct platform_device *pdev)
 	clk_disable(tegra->clk);
 	clk_put(tegra->clk);
 
-	if (tegra->clock_enabled){
+	if (tegra->clock_enabled) {
 		clk_disable(tegra->sclk_clk);
 		clk_disable(tegra->emc_clk);
 	}