usb: dwc2: gadget: add mutex to serialize init/deinit calls

This patch adds mutex, which protects initialization and
deinitialization procedures against suspend/resume methods. This mutex
will be needed by the updated suspend/resume calls, which tracks gadget
state.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 2cb0ac3..6b19755 100644 (file)
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -576,6 +576,7 @@ struct dwc2_hsotg {
        struct regulator_bulk_data supplies[ARRAY_SIZE(s3c_hsotg_supply_names)];
 
        spinlock_t lock;
+       struct mutex init_mutex;
        void *priv;
        int     irq;
        struct clk *clk;

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 3cd7891..6517334 100644 (file)
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -21,6 +21,7 @@
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/debugfs.h>
+#include <linux/mutex.h>
 #include <linux/seq_file.h>
 #include <linux/delay.h>
 #include <linux/io.h>
@@ -2866,6 +2867,7 @@ static int s3c_hsotg_udc_start(struct usb_gadget *gadget,
                return -EINVAL;
        }
 
+       mutex_lock(&hsotg->init_mutex);
        WARN_ON(hsotg->driver);
 
        driver->driver.bus = NULL;
@@ -2891,9 +2893,12 @@ static int s3c_hsotg_udc_start(struct usb_gadget *gadget,
 
        dev_info(hsotg->dev, "bound driver %s\n", driver->driver.name);
 
+       mutex_unlock(&hsotg->init_mutex);
+
        return 0;
 
 err:
+       mutex_unlock(&hsotg->init_mutex);
        hsotg->driver = NULL;
        return ret;
 }
@@ -2914,6 +2919,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget)
        if (!hsotg)
                return -ENODEV;
 
+       mutex_lock(&hsotg->init_mutex);
+
        /* all endpoints should be shutdown */
        for (ep = 1; ep < hsotg->num_of_eps; ep++)
                s3c_hsotg_ep_disable(&hsotg->eps[ep].ep);
@@ -2931,6 +2938,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget)
 
        clk_disable(hsotg->clk);
 
+       mutex_unlock(&hsotg->init_mutex);
+
        return 0;
 }
 
@@ -2959,6 +2968,7 @@ static int s3c_hsotg_pullup(struct usb_gadget *gadget, int is_on)
 
        dev_dbg(hsotg->dev, "%s: is_on: %d\n", __func__, is_on);
 
+       mutex_lock(&hsotg->init_mutex);
        spin_lock_irqsave(&hsotg->lock, flags);
        if (is_on) {
                clk_enable(hsotg->clk);
@@ -2970,6 +2980,7 @@ static int s3c_hsotg_pullup(struct usb_gadget *gadget, int is_on)
 
        hsotg->gadget.speed = USB_SPEED_UNKNOWN;
        spin_unlock_irqrestore(&hsotg->lock, flags);
+       mutex_unlock(&hsotg->init_mutex);
 
        return 0;
 }
@@ -3572,6 +3583,8 @@ int s3c_hsotg_suspend(struct dwc2_hsotg *hsotg)
        unsigned long flags;
        int ret = 0;
 
+       mutex_lock(&hsotg->init_mutex);
+
        if (hsotg->driver)
                dev_info(hsotg->dev, "suspending usb gadget %s\n",
                         hsotg->driver->driver.name);
@@ -3594,6 +3607,8 @@ int s3c_hsotg_suspend(struct dwc2_hsotg *hsotg)
                clk_disable(hsotg->clk);
        }
 
+       mutex_unlock(&hsotg->init_mutex);
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(s3c_hsotg_suspend);
@@ -3603,6 +3618,8 @@ int s3c_hsotg_resume(struct dwc2_hsotg *hsotg)
        unsigned long flags;
        int ret = 0;
 
+       mutex_lock(&hsotg->init_mutex);
+
        if (hsotg->driver) {
                dev_info(hsotg->dev, "resuming usb gadget %s\n",
                         hsotg->driver->driver.name);
@@ -3619,6 +3636,8 @@ int s3c_hsotg_resume(struct dwc2_hsotg *hsotg)
        s3c_hsotg_core_connect(hsotg);
        spin_unlock_irqrestore(&hsotg->lock, flags);
 
+       mutex_unlock(&hsotg->init_mutex);
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(s3c_hsotg_resume);

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 57eb8a3..ec5658a 100644 (file)
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -40,6 +40,7 @@
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/of_device.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 
 #include <linux/usb/of.h>
@@ -212,6 +213,7 @@ static int dwc2_driver_probe(struct platform_device *dev)
        hsotg->dr_mode = of_usb_get_dr_mode(dev->dev.of_node);
 
        spin_lock_init(&hsotg->lock);
+       mutex_init(&hsotg->init_mutex);
        retval = dwc2_gadget_init(hsotg, irq);
        if (retval)
                return retval;