diff mbox

[v3,1/2] usb: dwc2/gadget: add mutex to serialize init/deinit calls

Message ID 1414750354-19571-1-git-send-email-m.szyprowski@samsung.com
State New
Headers show

Commit Message

Marek Szyprowski Oct. 31, 2014, 10:12 a.m. UTC
This patch adds mutex, which protects initialization and
deinitialization procedures against suspend/resume methods.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/usb/dwc2/core.h   |  1 +
 drivers/usb/dwc2/gadget.c | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

Comments

Paul Zimmerman Oct. 31, 2014, 6:46 p.m. UTC | #1
> From: Marek Szyprowski [mailto:m.szyprowski@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.szyprowski@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?
Marek Szyprowski Nov. 13, 2014, 3:17 p.m. UTC | #2
Hello,

On 2014-10-31 19:46, Paul Zimmerman wrote:
>> From: Marek Szyprowski [mailto:m.szyprowski@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.szyprowski@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?

I've posted this version because I thought you were not convinced that 
the patch
"usb: dwc2/gadget: rework suspend/resume code to correctly restore 
gadget state"
can add code for initialization and deinitialization in suspend/resume 
paths.

Best regards
Paul Zimmerman Nov. 13, 2014, 8:55 p.m. UTC | #3
> From: Marek Szyprowski [mailto:m.szyprowski@samsung.com]

> Sent: Thursday, November 13, 2014 7:18 AM

> 

> On 2014-10-31 19:46, Paul Zimmerman wrote:

> >> From: Marek Szyprowski [mailto:m.szyprowski@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.szyprowski@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?

> 

> I've posted this version because I thought you were not convinced that

> the patch

> "usb: dwc2/gadget: rework suspend/resume code to correctly restore

> gadget state"

> can add code for initialization and deinitialization in suspend/resume

> paths.


My problem with that patch was that you were checking the ->enabled
flag outside of the spinlock. To address that, you only need to move
the check inside of the spinlock. I don't see why a mutex is needed.

-- 
Paul
Marek Szyprowski Nov. 14, 2014, 9:19 a.m. UTC | #4
Hello,

On 2014-11-13 21:55, Paul Zimmerman wrote:
>> From: Marek Szyprowski [mailto:m.szyprowski@samsung.com]
>> Sent: Thursday, November 13, 2014 7:18 AM
>>
>> On 2014-10-31 19:46, Paul Zimmerman wrote:
>>>> From: Marek Szyprowski [mailto:m.szyprowski@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.szyprowski@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?
>> I've posted this version because I thought you were not convinced that
>> the patch
>> "usb: dwc2/gadget: rework suspend/resume code to correctly restore
>> gadget state"
>> can add code for initialization and deinitialization in suspend/resume
>> paths.
> My problem with that patch was that you were checking the ->enabled
> flag outside of the spinlock. To address that, you only need to move
> the check inside of the spinlock. I don't see why a mutex is needed.

It is not that simple. I can add spin_lock() before checking enabled, 
but then
I would need to spin_unlock() to call regulator_bulk_enable() and 
phy_enable(),
because both cannot be called from atomic context. This means that the 
spinlock
in such case will not protect anything and is simply useless.

Best regards
Paul Zimmerman Nov. 14, 2014, 7:43 p.m. UTC | #5
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Felipe Balbi Nov. 14, 2014, 7:51 p.m. UTC | #6
Hi,

On Fri, Nov 14, 2014 at 07:43:23PM +0000, Paul Zimmerman wrote:
> > >>>> @@ -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?
> > >> I've posted this version because I thought you were not convinced that
> > >> the patch
> > >> "usb: dwc2/gadget: rework suspend/resume code to correctly restore
> > >> gadget state"
> > >> can add code for initialization and deinitialization in suspend/resume
> > >> paths.
> > > My problem with that patch was that you were checking the ->enabled
> > > flag outside of the spinlock. To address that, you only need to move
> > > the check inside of the spinlock. I don't see why a mutex is needed.
> > 
> > It is not that simple. I can add spin_lock() before checking enabled,
> > but then
> > I would need to spin_unlock() to call regulator_bulk_enable() and
> > phy_enable(),
> > because both cannot be called from atomic context. This means that the
> > spinlock
> > in such case will not protect anything and is simply useless.
> 
> Ah, OK. So you're using the mutex instead of the ->enabled flag that you
> proposed in the "rework suspend/resume code" patch. So this patch is a
> replacement for that one. Somehow I was thinking this patch was on top
> of that one.
> 
> So I guess this is OK, but I would like to get Felipe's opinion about
> it before we apply this.
> 
> Felipe?

I can't think of a better way, I'm afraid :-(
Paul Zimmerman Nov. 18, 2014, 9 p.m. UTC | #7
> From: Marek Szyprowski [mailto:m.szyprowski@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.szyprowski@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;
>  }
> 

Acked-by: Paul Zimmerman <paulz@synopsys.com>

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Felipe Balbi Nov. 20, 2014, 7:53 p.m. UTC | #8
On Fri, Oct 31, 2014 at 11:12:33AM +0100, Marek Szyprowski wrote:
> This patch adds mutex, which protects initialization and
> deinitialization procedures against suspend/resume methods.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

doesn't apply either:

checking file drivers/usb/dwc2/core.h
Hunk #1 FAILED at 187.
1 out of 1 hunk FAILED
checking file drivers/usb/dwc2/gadget.c
Hunk #2 succeeded at 2863 (offset -46 lines).
Hunk #3 succeeded at 2889 (offset -46 lines).
Hunk #4 succeeded at 2915 (offset -47 lines).
Hunk #5 succeeded at 2934 (offset -47 lines).
Hunk #6 succeeded at 2964 (offset -47 lines).
Hunk #7 succeeded at 2976 (offset -47 lines).
Hunk #8 FAILED at 3518.
Hunk #9 succeeded at 3579 (offset -84 lines).
Hunk #10 succeeded at 3603 with fuzz 1 (offset -84 lines).
Hunk #11 succeeded at 3614 (offset -84 lines).
Hunk #12 succeeded at 3632 with fuzz 1 (offset -84 lines).
1 out of 12 hunks FAILED

please rebase on testing/next. Also, add Paul's Ack when doing so ;-)

thanks
diff mbox

Patch

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;
 }