> From: Marek Szyprowski [mailto:m.szyprow...@samsung.com] > Sent: Friday, October 31, 2014 3:13 AM > > This patch adds mutex, which protects initialization and > deinitialization procedures against suspend/resume methods. > > Signed-off-by: Marek Szyprowski <m.szyprow...@samsung.com> > --- > drivers/usb/dwc2/core.h | 1 + > drivers/usb/dwc2/gadget.c | 20 ++++++++++++++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h > index 9f77b4d1c5ff..58732a9a0019 100644 > --- a/drivers/usb/dwc2/core.h > +++ b/drivers/usb/dwc2/core.h > @@ -187,6 +187,7 @@ struct s3c_hsotg { > struct s3c_hsotg_plat *plat; > > spinlock_t lock; > + struct mutex init_mutex; > > void __iomem *regs; > int irq; > diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c > index d8dda39c9e16..a2e4272a904e 100644 > --- 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> > @@ -2908,6 +2909,7 @@ 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; > @@ -2933,9 +2935,12 @@ 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; > } > @@ -2957,6 +2962,8 @@ 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); > @@ -2974,6 +2981,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget, > > clk_disable(hsotg->clk); > > + mutex_unlock(&hsotg->init_mutex); > + > return 0; > } > > @@ -3002,6 +3011,7 @@ 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); > @@ -3013,6 +3023,7 @@ 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; > } > @@ -3507,6 +3518,7 @@ static int s3c_hsotg_probe(struct platform_device *pdev) > } > > spin_lock_init(&hsotg->lock); > + mutex_init(&hsotg->init_mutex); > > hsotg->irq = ret; > > @@ -3652,6 +3664,8 @@ static int s3c_hsotg_suspend(struct platform_device > *pdev, pm_message_t state) > 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); > @@ -3674,6 +3688,8 @@ static int s3c_hsotg_suspend(struct platform_device > *pdev, pm_message_t state) > clk_disable(hsotg->clk); > } > > + mutex_unlock(&hsotg->init_mutex); > + > return ret; > } > > @@ -3683,7 +3699,9 @@ static int s3c_hsotg_resume(struct platform_device > *pdev) > 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); > > @@ -3699,6 +3717,8 @@ static int s3c_hsotg_resume(struct platform_device > *pdev) > s3c_hsotg_core_connect(hsotg); > spin_unlock_irqrestore(&hsotg->lock, flags); > > + mutex_unlock(&hsotg->init_mutex); > + > return ret; > } >
Hmm. I can't find any other UDC driver that uses a mutex in its suspend/resume functions. Can you explain why this is needed only for dwc2? -- Paul -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
