[PATCH v2 0/2] usb/gadget: independent registration of gadgets and gadget

[PATCH v2 0/2] usb/gadget: independent registration of gadgets and gadget

[Ruslan Bilovol]

This patchset adds independent registration of gadgets
and gadget drivers to udc-core. This is very useful for
built-in modules into kernel case since it's possible
situation that gadget driver is probing at a time
when no gadgets are registered in udc-core.
In this case instead of silently failing without
of any attempt to recover, with independent registration
of gadgets and gadget drivers there is no matter
in which order gadgets and gadget drivers are
probed/registered.

This patch has side-effect on gadget drivers that had
__init/__exit attributes on some paths like bind/unbind
and (since bind/unbind may happen at any time) should
not use them now. This is covered by second patch
(please let me know if I need to break it into separate
patches for each gadget driver)
 
=====================
v2:
 - changed first patch to have only deferred probe part
   (because Gadget Bus seems to be better variant when
   some more complicated behavior will be required)
 - rebased to latest 'next' branch of Felipe Balbi's tree

Ruslan Bilovol (2):
  usb: gadget: udc-core: independent registration of gadgets and gadget
    drivers
  usb: gadget: legacy: don't use __init/__exit attributes for
    bind/unbind path

 drivers/usb/gadget/legacy/acm_ms.c       |  6 +--
 drivers/usb/gadget/legacy/audio.c        |  6 +--
 drivers/usb/gadget/legacy/cdc2.c         |  6 +--
 drivers/usb/gadget/legacy/dbgp.c         |  2 +-
 drivers/usb/gadget/legacy/ether.c        |  8 ++--
 drivers/usb/gadget/legacy/gmidi.c        |  6 +--
 drivers/usb/gadget/legacy/hid.c          |  6 +--
 drivers/usb/gadget/legacy/mass_storage.c |  4 +-
 drivers/usb/gadget/legacy/multi.c        | 16 +++----
 drivers/usb/gadget/legacy/ncm.c          |  6 +--
 drivers/usb/gadget/legacy/nokia.c        |  6 +--
 drivers/usb/gadget/legacy/printer.c      |  6 +--
 drivers/usb/gadget/legacy/serial.c       |  2 +-
 drivers/usb/gadget/legacy/webcam.c       |  4 +-
 drivers/usb/gadget/legacy/zero.c         |  2 +-
 drivers/usb/gadget/udc/udc-core.c        | 77 ++++++++++++++++++++++++++++++--
 16 files changed, 117 insertions(+), 46 deletions(-)

-- 
1.9.1

[PATCH v2 1/2] usb: gadget: udc-core: independent registration of gadgets and gadget drivers

[Ruslan Bilovol]

Change behavior during registration of gadgets and
gadget drivers in udc-core. Instead of previous
approach when for successful probe of usb gadget driver
at least one usb gadget should be already registered
use another one where gadget drivers and gadgets
can be registered in udc-core independently.

Independent registration of gadgets and gadget drivers
is useful for built-in into kernel gadget and gadget
driver case - because it's possible that gadget is
really probed only on late_init stage (due to deferred
probe) whereas gadget driver's probe is silently failed
on module_init stage due to no any UDC added.

Also it is useful for modules case - now there is no
difference what module to insert first: gadget module
or gadget driver one.

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
---
 drivers/usb/gadget/udc/udc-core.c | 77 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 74 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index 5a81cb0..71b6942 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -46,10 +46,18 @@ struct usb_udc {
 	struct list_head		list;
 };
 
+struct pending_gadget_driver {
+	struct usb_gadget_driver	*driver;
+	char				*udc_name;
+	struct list_head		list;
+};
+
 static struct class *udc_class;
 static LIST_HEAD(udc_list);
+static LIST_HEAD(gadget_driver_pending_list);
 static DEFINE_MUTEX(udc_lock);
 
+static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver);
 /* ------------------------------------------------------------------------- */
 
 #ifdef	CONFIG_HAS_DMA
@@ -244,6 +252,7 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 {
 	struct usb_udc		*udc;
 	int			ret = -ENOMEM;
+	struct pending_gadget_driver *pending;
 
 	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
 	if (!udc)
@@ -288,6 +297,24 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 
 	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
 
+	if (!list_empty(&gadget_driver_pending_list)) {
+		pending = list_first_entry(&gadget_driver_pending_list,
+					struct pending_gadget_driver, list);
+
+		if (pending->udc_name) {
+			if (!strcmp(pending->udc_name, dev_name(&udc->dev))) {
+				udc_bind_to_driver(udc, pending->driver);
+				list_del(&pending->list);
+				kfree(pending->udc_name);
+				kfree(pending);
+			}
+		} else {
+			udc_bind_to_driver(udc, pending->driver);
+			list_del(&pending->list);
+			kfree(pending);
+		}
+	}
+
 	mutex_unlock(&udc_lock);
 
 	return 0;
@@ -423,7 +450,27 @@ int usb_udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
 			break;
 	}
 	if (ret) {
-		ret = -ENODEV;
+		struct pending_gadget_driver *pending;
+
+		pending = kzalloc(sizeof(*pending), GFP_KERNEL);
+		if (!pending) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		pending->driver = driver;
+		pending->udc_name = kstrdup(name, GFP_KERNEL);
+		if (!pending->udc_name) {
+			kfree(pending);
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		list_add_tail(&pending->list, &gadget_driver_pending_list);
+
+		pr_info("udc-core: couldn't find the [%s] UDC "
+				"- added [%s] to list of pending drivers\n",
+				name, driver->function);
+		ret = 0;
 		goto out;
 	}
 	if (udc->driver) {
@@ -440,6 +487,7 @@ EXPORT_SYMBOL_GPL(usb_udc_attach_driver);
 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 {
 	struct usb_udc		*udc = NULL;
+	struct pending_gadget_driver *pending;
 	int			ret;
 
 	if (!driver || !driver->bind || !driver->setup)
@@ -452,9 +500,20 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 			goto found;
 	}
 
-	pr_debug("couldn't find an available UDC\n");
+	pending = kzalloc(sizeof(*pending), GFP_KERNEL);
+	if (!pending) {
+		mutex_unlock(&udc_lock);
+		return -ENOMEM;
+	}
+	pending->driver = driver;
+	list_add_tail(&pending->list, &gadget_driver_pending_list);
+
+	pr_info("udc-core: couldn't find an available UDC "
+			"- add [%s] to list of pending drivers\n",
+			driver->function);
+
 	mutex_unlock(&udc_lock);
-	return -ENODEV;
+	return 0;
 found:
 	ret = udc_bind_to_driver(udc, driver);
 	mutex_unlock(&udc_lock);
@@ -465,6 +524,7 @@ EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 {
 	struct usb_udc		*udc = NULL;
+	struct pending_gadget_driver *pending = NULL;
 	int			ret = -ENODEV;
 
 	if (!driver || !driver->unbind)
@@ -480,6 +540,17 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 			break;
 		}
 
+	if (ret) {
+		list_for_each_entry(pending, &gadget_driver_pending_list, list)
+			if (pending->driver == driver) {
+				list_del(&pending->list);
+				kfree(pending->udc_name);
+				kfree(pending);
+				ret = 0;
+				break;
+			}
+	}
+
 	mutex_unlock(&udc_lock);
 	return ret;
 }
-- 
1.9.1

Re: [PATCH v2 1/2] usb: gadget: udc-core: independent registration of gadgets and gadget drivers

[Alan Stern]

On Mon, 16 Feb 2015, Ruslan Bilovol wrote:

> Change behavior during registration of gadgets and
> gadget drivers in udc-core. Instead of previous
> approach when for successful probe of usb gadget driver
> at least one usb gadget should be already registered
> use another one where gadget drivers and gadgets
> can be registered in udc-core independently.
> 
> Independent registration of gadgets and gadget drivers
> is useful for built-in into kernel gadget and gadget
> driver case - because it's possible that gadget is
> really probed only on late_init stage (due to deferred
> probe) whereas gadget driver's probe is silently failed
> on module_init stage due to no any UDC added.
> 
> Also it is useful for modules case - now there is no
> difference what module to insert first: gadget module
> or gadget driver one.
> 
> Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
> ---
>  drivers/usb/gadget/udc/udc-core.c | 77 +++++++++++++++++++++++++++++++++++++--
>  1 file changed, 74 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
> index 5a81cb0..71b6942 100644
> --- a/drivers/usb/gadget/udc/udc-core.c
> +++ b/drivers/usb/gadget/udc/udc-core.c
> @@ -46,10 +46,18 @@ struct usb_udc {
>  	struct list_head		list;
>  };
>  
> +struct pending_gadget_driver {
> +	struct usb_gadget_driver	*driver;
> +	char				*udc_name;
> +	struct list_head		list;
> +};

Don't make this a separate structure.  It should be embedded in the 
usb_gadget_driver structure.  This will make a lot of the changes below 
much simpler.

> @@ -288,6 +297,24 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
>  
>  	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
>  
> +	if (!list_empty(&gadget_driver_pending_list)) {
> +		pending = list_first_entry(&gadget_driver_pending_list,
> +					struct pending_gadget_driver, list);
> +
> +		if (pending->udc_name) {
> +			if (!strcmp(pending->udc_name, dev_name(&udc->dev))) {
> +				udc_bind_to_driver(udc, pending->driver);
> +				list_del(&pending->list);
> +				kfree(pending->udc_name);
> +				kfree(pending);
> +			}
> +		} else {
> +			udc_bind_to_driver(udc, pending->driver);
> +			list_del(&pending->list);
> +			kfree(pending);
> +		}

This code can be simplified too:

		if (!pending->udc_name || strcmp(pending->udc_name, 
				dev_name(&udc->dev) == 0) {
			...
> +	}
> +
>  	mutex_unlock(&udc_lock);
>  
>  	return 0;

Don't you want to add a driver back to the pending list 
usb_del_gadget_udc() after the call to usb_gadget_remove_driver?

> @@ -423,7 +450,27 @@ int usb_udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
>  			break;
>  	}
>  	if (ret) {
> -		ret = -ENODEV;
> +		struct pending_gadget_driver *pending;
> +
> +		pending = kzalloc(sizeof(*pending), GFP_KERNEL);
> +		if (!pending) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +		pending->driver = driver;
> +		pending->udc_name = kstrdup(name, GFP_KERNEL);
> +		if (!pending->udc_name) {
> +			kfree(pending);
> +			ret = -ENOMEM;
> +			goto out;
> +		}

Why do you need to copy the name?  Just use the original.

Alan Stern

Re: [PATCH v2 1/2] usb: gadget: udc-core: independent registration of gadgets and gadget drivers

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 1861 bytes --]

On Sun, Feb 15, 2015 at 06:23:02PM -0500, Alan Stern wrote:
> On Mon, 16 Feb 2015, Ruslan Bilovol wrote:
> 
> > Change behavior during registration of gadgets and
> > gadget drivers in udc-core. Instead of previous
> > approach when for successful probe of usb gadget driver
> > at least one usb gadget should be already registered
> > use another one where gadget drivers and gadgets
> > can be registered in udc-core independently.
> > 
> > Independent registration of gadgets and gadget drivers
> > is useful for built-in into kernel gadget and gadget
> > driver case - because it's possible that gadget is
> > really probed only on late_init stage (due to deferred
> > probe) whereas gadget driver's probe is silently failed
> > on module_init stage due to no any UDC added.
> > 
> > Also it is useful for modules case - now there is no
> > difference what module to insert first: gadget module
> > or gadget driver one.
> > 
> > Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
> > ---
> >  drivers/usb/gadget/udc/udc-core.c | 77 +++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 74 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
> > index 5a81cb0..71b6942 100644
> > --- a/drivers/usb/gadget/udc/udc-core.c
> > +++ b/drivers/usb/gadget/udc/udc-core.c
> > @@ -46,10 +46,18 @@ struct usb_udc {
> >  	struct list_head		list;
> >  };
> >  
> > +struct pending_gadget_driver {
> > +	struct usb_gadget_driver	*driver;
> > +	char				*udc_name;
> > +	struct list_head		list;
> > +};
> 
> Don't make this a separate structure.  It should be embedded in the
> usb_gadget_driver structure.  This will make a lot of the changes
> below much simpler.

right, also when resending, make sure to Cc linux-usb as well.

-- 
balbi

[-- Attachment #2: Digital signature --]
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Re: [PATCH v2 1/2] usb: gadget: udc-core: independent registration of gadgets and gadget drivers

[Ruslan Bilovol]

On Mon, Feb 16, 2015 at 1:23 AM, Alan Stern <stern@rowland.harvard.edu> wrote:
> On Mon, 16 Feb 2015, Ruslan Bilovol wrote:
>
>> Change behavior during registration of gadgets and
>> gadget drivers in udc-core. Instead of previous
>> approach when for successful probe of usb gadget driver
>> at least one usb gadget should be already registered
>> use another one where gadget drivers and gadgets
>> can be registered in udc-core independently.
>>
>> Independent registration of gadgets and gadget drivers
>> is useful for built-in into kernel gadget and gadget
>> driver case - because it's possible that gadget is
>> really probed only on late_init stage (due to deferred
>> probe) whereas gadget driver's probe is silently failed
>> on module_init stage due to no any UDC added.
>>
>> Also it is useful for modules case - now there is no
>> difference what module to insert first: gadget module
>> or gadget driver one.
>>
>> Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
>> ---
>>  drivers/usb/gadget/udc/udc-core.c | 77 +++++++++++++++++++++++++++++++++++++--
>>  1 file changed, 74 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
>> index 5a81cb0..71b6942 100644
>> --- a/drivers/usb/gadget/udc/udc-core.c
>> +++ b/drivers/usb/gadget/udc/udc-core.c
>> @@ -46,10 +46,18 @@ struct usb_udc {
>>       struct list_head                list;
>>  };
>>
>> +struct pending_gadget_driver {
>> +     struct usb_gadget_driver        *driver;
>> +     char                            *udc_name;
>> +     struct list_head                list;
>> +};
>
> Don't make this a separate structure.  It should be embedded in the
> usb_gadget_driver structure.  This will make a lot of the changes below
> much simpler.

Yes, but require more changes across gadget sources. Will do it in next version

>
>> @@ -288,6 +297,24 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
>>
>>       usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
>>
>> +     if (!list_empty(&gadget_driver_pending_list)) {
>> +             pending = list_first_entry(&gadget_driver_pending_list,
>> +                                     struct pending_gadget_driver, list);
>> +
>> +             if (pending->udc_name) {
>> +                     if (!strcmp(pending->udc_name, dev_name(&udc->dev))) {
>> +                             udc_bind_to_driver(udc, pending->driver);
>> +                             list_del(&pending->list);
>> +                             kfree(pending->udc_name);
>> +                             kfree(pending);
>> +                     }
>> +             } else {
>> +                     udc_bind_to_driver(udc, pending->driver);
>> +                     list_del(&pending->list);
>> +                     kfree(pending);
>> +             }
>
> This code can be simplified too:
>
>                 if (!pending->udc_name || strcmp(pending->udc_name,
>                                 dev_name(&udc->dev) == 0) {
>                         ...

Good catch!

>> +     }
>> +
>>       mutex_unlock(&udc_lock);
>>
>>       return 0;
>
> Don't you want to add a driver back to the pending list
> usb_del_gadget_udc() after the call to usb_gadget_remove_driver?

Will be added in next version, should be few lines change

>
>> @@ -423,7 +450,27 @@ int usb_udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
>>                       break;
>>       }
>>       if (ret) {
>> -             ret = -ENODEV;
>> +             struct pending_gadget_driver *pending;
>> +
>> +             pending = kzalloc(sizeof(*pending), GFP_KERNEL);
>> +             if (!pending) {
>> +                     ret = -ENOMEM;
>> +                     goto out;
>> +             }
>> +             pending->driver = driver;
>> +             pending->udc_name = kstrdup(name, GFP_KERNEL);
>> +             if (!pending->udc_name) {
>> +                     kfree(pending);
>> +                     ret = -ENOMEM;
>> +                     goto out;
>> +             }
>
> Why do you need to copy the name?  Just use the original.

Because it's only place we keep it. Will not be needed in next version of patch

Best regards,
Ruslan

>
> Alan Stern
>

[PATCH v2 2/2] usb: gadget: legacy: don't use __init/__exit attributes for bind/unbind path

[Ruslan Bilovol]

Since it's possible now to do independent gadget and
gadget driver registration in udc-core, some of the
functions can't have __init/__exit attributes (almost
bind/unbind callbacks are affected)

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
---
 drivers/usb/gadget/legacy/acm_ms.c       |  6 +++---
 drivers/usb/gadget/legacy/audio.c        |  6 +++---
 drivers/usb/gadget/legacy/cdc2.c         |  6 +++---
 drivers/usb/gadget/legacy/dbgp.c         |  2 +-
 drivers/usb/gadget/legacy/ether.c        |  8 ++++----
 drivers/usb/gadget/legacy/gmidi.c        |  6 +++---
 drivers/usb/gadget/legacy/hid.c          |  6 +++---
 drivers/usb/gadget/legacy/mass_storage.c |  4 ++--
 drivers/usb/gadget/legacy/multi.c        | 16 ++++++++--------
 drivers/usb/gadget/legacy/ncm.c          |  6 +++---
 drivers/usb/gadget/legacy/nokia.c        |  6 +++---
 drivers/usb/gadget/legacy/printer.c      |  6 +++---
 drivers/usb/gadget/legacy/serial.c       |  2 +-
 drivers/usb/gadget/legacy/webcam.c       |  4 ++--
 drivers/usb/gadget/legacy/zero.c         |  2 +-
 15 files changed, 43 insertions(+), 43 deletions(-)

diff --git a/drivers/usb/gadget/legacy/acm_ms.c b/drivers/usb/gadget/legacy/acm_ms.c
index c30b7b5..3a48aab 100644
--- a/drivers/usb/gadget/legacy/acm_ms.c
+++ b/drivers/usb/gadget/legacy/acm_ms.c
@@ -121,7 +121,7 @@ static struct usb_function *f_msg;
 /*
  * We _always_ have both ACM and mass storage functions.
  */
-static int __init acm_ms_do_config(struct usb_configuration *c)
+static int acm_ms_do_config(struct usb_configuration *c)
 {
 	struct fsg_opts *opts;
 	int	status;
@@ -174,7 +174,7 @@ static struct usb_configuration acm_ms_config_driver = {
 
 /*-------------------------------------------------------------------------*/
 
-static int __init acm_ms_bind(struct usb_composite_dev *cdev)
+static int acm_ms_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget	*gadget = cdev->gadget;
 	struct fsg_opts		*opts;
@@ -249,7 +249,7 @@ fail_get_msg:
 	return status;
 }
 
-static int __exit acm_ms_unbind(struct usb_composite_dev *cdev)
+static int acm_ms_unbind(struct usb_composite_dev *cdev)
 {
 	usb_put_function(f_msg);
 	usb_put_function_instance(fi_msg);
diff --git a/drivers/usb/gadget/legacy/audio.c b/drivers/usb/gadget/legacy/audio.c
index f46a395..ba95518 100644
--- a/drivers/usb/gadget/legacy/audio.c
+++ b/drivers/usb/gadget/legacy/audio.c
@@ -167,7 +167,7 @@ static const struct usb_descriptor_header *otg_desc[] = {
 
 /*-------------------------------------------------------------------------*/
 
-static int __init audio_do_config(struct usb_configuration *c)
+static int audio_do_config(struct usb_configuration *c)
 {
 	int status;
 
@@ -216,7 +216,7 @@ static struct usb_configuration audio_config_driver = {
 
 /*-------------------------------------------------------------------------*/
 
-static int __init audio_bind(struct usb_composite_dev *cdev)
+static int audio_bind(struct usb_composite_dev *cdev)
 {
 #ifndef CONFIG_GADGET_UAC1
 	struct f_uac2_opts	*uac2_opts;
@@ -276,7 +276,7 @@ fail:
 	return status;
 }
 
-static int __exit audio_unbind(struct usb_composite_dev *cdev)
+static int audio_unbind(struct usb_composite_dev *cdev)
 {
 #ifdef CONFIG_GADGET_UAC1
 	if (!IS_ERR_OR_NULL(f_uac1))
diff --git a/drivers/usb/gadget/legacy/cdc2.c b/drivers/usb/gadget/legacy/cdc2.c
index 2e85d94..8d1985c 100644
--- a/drivers/usb/gadget/legacy/cdc2.c
+++ b/drivers/usb/gadget/legacy/cdc2.c
@@ -104,7 +104,7 @@ static struct usb_function_instance *fi_ecm;
 /*
  * We _always_ have both CDC ECM and CDC ACM functions.
  */
-static int __init cdc_do_config(struct usb_configuration *c)
+static int cdc_do_config(struct usb_configuration *c)
 {
 	int	status;
 
@@ -153,7 +153,7 @@ static struct usb_configuration cdc_config_driver = {
 
 /*-------------------------------------------------------------------------*/
 
-static int __init cdc_bind(struct usb_composite_dev *cdev)
+static int cdc_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget	*gadget = cdev->gadget;
 	struct f_ecm_opts	*ecm_opts;
@@ -211,7 +211,7 @@ fail:
 	return status;
 }
 
-static int __exit cdc_unbind(struct usb_composite_dev *cdev)
+static int cdc_unbind(struct usb_composite_dev *cdev)
 {
 	usb_put_function(f_acm);
 	usb_put_function_instance(fi_serial);
diff --git a/drivers/usb/gadget/legacy/dbgp.c b/drivers/usb/gadget/legacy/dbgp.c
index 633683a..7c42b01 100644
--- a/drivers/usb/gadget/legacy/dbgp.c
+++ b/drivers/usb/gadget/legacy/dbgp.c
@@ -284,7 +284,7 @@ fail_1:
 	return -ENODEV;
 }
 
-static int __init dbgp_bind(struct usb_gadget *gadget,
+static int dbgp_bind(struct usb_gadget *gadget,
 		struct usb_gadget_driver *driver)
 {
 	int err, stp;
diff --git a/drivers/usb/gadget/legacy/ether.c b/drivers/usb/gadget/legacy/ether.c
index c5fdc61..4283969 100644
--- a/drivers/usb/gadget/legacy/ether.c
+++ b/drivers/usb/gadget/legacy/ether.c
@@ -222,7 +222,7 @@ static struct usb_function *f_rndis;
  * the first one present.  That's to make Microsoft's drivers happy,
  * and to follow DOCSIS 1.0 (cable modem standard).
  */
-static int __init rndis_do_config(struct usb_configuration *c)
+static int rndis_do_config(struct usb_configuration *c)
 {
 	int status;
 
@@ -264,7 +264,7 @@ MODULE_PARM_DESC(use_eem, "use CDC EEM mode");
 /*
  * We _always_ have an ECM, CDC Subset, or EEM configuration.
  */
-static int __init eth_do_config(struct usb_configuration *c)
+static int eth_do_config(struct usb_configuration *c)
 {
 	int status = 0;
 
@@ -318,7 +318,7 @@ static struct usb_configuration eth_config_driver = {
 
 /*-------------------------------------------------------------------------*/
 
-static int __init eth_bind(struct usb_composite_dev *cdev)
+static int eth_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget	*gadget = cdev->gadget;
 	struct f_eem_opts	*eem_opts = NULL;
@@ -447,7 +447,7 @@ fail:
 	return status;
 }
 
-static int __exit eth_unbind(struct usb_composite_dev *cdev)
+static int eth_unbind(struct usb_composite_dev *cdev)
 {
 	if (has_rndis()) {
 		usb_put_function(f_rndis);
diff --git a/drivers/usb/gadget/legacy/gmidi.c b/drivers/usb/gadget/legacy/gmidi.c
index e02a095..c098281 100644
--- a/drivers/usb/gadget/legacy/gmidi.c
+++ b/drivers/usb/gadget/legacy/gmidi.c
@@ -118,7 +118,7 @@ static struct usb_gadget_strings *dev_strings[] = {
 static struct usb_function_instance *fi_midi;
 static struct usb_function *f_midi;
 
-static int __exit midi_unbind(struct usb_composite_dev *dev)
+static int midi_unbind(struct usb_composite_dev *dev)
 {
 	usb_put_function(f_midi);
 	usb_put_function_instance(fi_midi);
@@ -133,7 +133,7 @@ static struct usb_configuration midi_config = {
 	.MaxPower	= CONFIG_USB_GADGET_VBUS_DRAW,
 };
 
-static int __init midi_bind_config(struct usb_configuration *c)
+static int midi_bind_config(struct usb_configuration *c)
 {
 	int status;
 
@@ -150,7 +150,7 @@ static int __init midi_bind_config(struct usb_configuration *c)
 	return 0;
 }
 
-static int __init midi_bind(struct usb_composite_dev *cdev)
+static int midi_bind(struct usb_composite_dev *cdev)
 {
 	struct f_midi_opts *midi_opts;
 	int status;
diff --git a/drivers/usb/gadget/legacy/hid.c b/drivers/usb/gadget/legacy/hid.c
index 614b06d..11de01b 100644
--- a/drivers/usb/gadget/legacy/hid.c
+++ b/drivers/usb/gadget/legacy/hid.c
@@ -106,7 +106,7 @@ static struct usb_gadget_strings *dev_strings[] = {
 
 /****************************** Configurations ******************************/
 
-static int __init do_config(struct usb_configuration *c)
+static int do_config(struct usb_configuration *c)
 {
 	struct hidg_func_node *e, *n;
 	int status = 0;
@@ -147,7 +147,7 @@ static struct usb_configuration config_driver = {
 
 /****************************** Gadget Bind ******************************/
 
-static int __init hid_bind(struct usb_composite_dev *cdev)
+static int hid_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget *gadget = cdev->gadget;
 	struct list_head *tmp;
@@ -205,7 +205,7 @@ put:
 	return status;
 }
 
-static int __exit hid_unbind(struct usb_composite_dev *cdev)
+static int hid_unbind(struct usb_composite_dev *cdev)
 {
 	struct hidg_func_node *n;
 
diff --git a/drivers/usb/gadget/legacy/mass_storage.c b/drivers/usb/gadget/legacy/mass_storage.c
index 8e27a8c..d169d43 100644
--- a/drivers/usb/gadget/legacy/mass_storage.c
+++ b/drivers/usb/gadget/legacy/mass_storage.c
@@ -130,7 +130,7 @@ static int msg_thread_exits(struct fsg_common *common)
 	return 0;
 }
 
-static int __init msg_do_config(struct usb_configuration *c)
+static int msg_do_config(struct usb_configuration *c)
 {
 	struct fsg_opts *opts;
 	int ret;
@@ -170,7 +170,7 @@ static struct usb_configuration msg_config_driver = {
 
 /****************************** Gadget Bind ******************************/
 
-static int __init msg_bind(struct usb_composite_dev *cdev)
+static int msg_bind(struct usb_composite_dev *cdev)
 {
 	static const struct fsg_operations ops = {
 		.thread_exits = msg_thread_exits,
diff --git a/drivers/usb/gadget/legacy/multi.c b/drivers/usb/gadget/legacy/multi.c
index 39d27bb..4a4a1a1 100644
--- a/drivers/usb/gadget/legacy/multi.c
+++ b/drivers/usb/gadget/legacy/multi.c
@@ -149,7 +149,7 @@ static struct usb_function *f_acm_rndis;
 static struct usb_function *f_rndis;
 static struct usb_function *f_msg_rndis;
 
-static __init int rndis_do_config(struct usb_configuration *c)
+static int rndis_do_config(struct usb_configuration *c)
 {
 	struct fsg_opts *fsg_opts;
 	int ret;
@@ -206,7 +206,7 @@ err_func_rndis:
 	return ret;
 }
 
-static __ref int rndis_config_register(struct usb_composite_dev *cdev)
+static int rndis_config_register(struct usb_composite_dev *cdev)
 {
 	static struct usb_configuration config = {
 		.bConfigurationValue	= MULTI_RNDIS_CONFIG_NUM,
@@ -221,7 +221,7 @@ static __ref int rndis_config_register(struct usb_composite_dev *cdev)
 
 #else
 
-static __ref int rndis_config_register(struct usb_composite_dev *cdev)
+static int rndis_config_register(struct usb_composite_dev *cdev)
 {
 	return 0;
 }
@@ -237,7 +237,7 @@ static struct usb_function *f_acm_multi;
 static struct usb_function *f_ecm;
 static struct usb_function *f_msg_multi;
 
-static __init int cdc_do_config(struct usb_configuration *c)
+static int cdc_do_config(struct usb_configuration *c)
 {
 	struct fsg_opts *fsg_opts;
 	int ret;
@@ -295,7 +295,7 @@ err_func_ecm:
 	return ret;
 }
 
-static __ref int cdc_config_register(struct usb_composite_dev *cdev)
+static int cdc_config_register(struct usb_composite_dev *cdev)
 {
 	static struct usb_configuration config = {
 		.bConfigurationValue	= MULTI_CDC_CONFIG_NUM,
@@ -310,7 +310,7 @@ static __ref int cdc_config_register(struct usb_composite_dev *cdev)
 
 #else
 
-static __ref int cdc_config_register(struct usb_composite_dev *cdev)
+static int cdc_config_register(struct usb_composite_dev *cdev)
 {
 	return 0;
 }
@@ -321,7 +321,7 @@ static __ref int cdc_config_register(struct usb_composite_dev *cdev)
 
 /****************************** Gadget Bind ******************************/
 
-static int __ref multi_bind(struct usb_composite_dev *cdev)
+static int multi_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget *gadget = cdev->gadget;
 #ifdef CONFIG_USB_G_MULTI_CDC
@@ -466,7 +466,7 @@ fail:
 	return status;
 }
 
-static int __exit multi_unbind(struct usb_composite_dev *cdev)
+static int multi_unbind(struct usb_composite_dev *cdev)
 {
 #ifdef CONFIG_USB_G_MULTI_CDC
 	usb_put_function(f_msg_multi);
diff --git a/drivers/usb/gadget/legacy/ncm.c b/drivers/usb/gadget/legacy/ncm.c
index e90e23d..fb14e0c 100644
--- a/drivers/usb/gadget/legacy/ncm.c
+++ b/drivers/usb/gadget/legacy/ncm.c
@@ -107,7 +107,7 @@ static struct usb_function *f_ncm;
 
 /*-------------------------------------------------------------------------*/
 
-static int __init ncm_do_config(struct usb_configuration *c)
+static int ncm_do_config(struct usb_configuration *c)
 {
 	int status;
 
@@ -143,7 +143,7 @@ static struct usb_configuration ncm_config_driver = {
 
 /*-------------------------------------------------------------------------*/
 
-static int __init gncm_bind(struct usb_composite_dev *cdev)
+static int gncm_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget	*gadget = cdev->gadget;
 	struct f_ncm_opts	*ncm_opts;
@@ -186,7 +186,7 @@ fail:
 	return status;
 }
 
-static int __exit gncm_unbind(struct usb_composite_dev *cdev)
+static int gncm_unbind(struct usb_composite_dev *cdev)
 {
 	if (!IS_ERR_OR_NULL(f_ncm))
 		usb_put_function(f_ncm);
diff --git a/drivers/usb/gadget/legacy/nokia.c b/drivers/usb/gadget/legacy/nokia.c
index 9b8fd70..7ad8398 100644
--- a/drivers/usb/gadget/legacy/nokia.c
+++ b/drivers/usb/gadget/legacy/nokia.c
@@ -118,7 +118,7 @@ static struct usb_function_instance *fi_obex1;
 static struct usb_function_instance *fi_obex2;
 static struct usb_function_instance *fi_phonet;
 
-static int __init nokia_bind_config(struct usb_configuration *c)
+static int nokia_bind_config(struct usb_configuration *c)
 {
 	struct usb_function *f_acm;
 	struct usb_function *f_phonet = NULL;
@@ -224,7 +224,7 @@ err_get_acm:
 	return status;
 }
 
-static int __init nokia_bind(struct usb_composite_dev *cdev)
+static int nokia_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget	*gadget = cdev->gadget;
 	int			status;
@@ -307,7 +307,7 @@ err_usb:
 	return status;
 }
 
-static int __exit nokia_unbind(struct usb_composite_dev *cdev)
+static int nokia_unbind(struct usb_composite_dev *cdev)
 {
 	if (!IS_ERR_OR_NULL(f_obex1_cfg2))
 		usb_put_function(f_obex1_cfg2);
diff --git a/drivers/usb/gadget/legacy/printer.c b/drivers/usb/gadget/legacy/printer.c
index 9054598..da2a89b 100644
--- a/drivers/usb/gadget/legacy/printer.c
+++ b/drivers/usb/gadget/legacy/printer.c
@@ -1034,7 +1034,7 @@ unknown:
 	return value;
 }
 
-static int __init printer_func_bind(struct usb_configuration *c,
+static int printer_func_bind(struct usb_configuration *c,
 		struct usb_function *f)
 {
 	struct printer_dev *dev = container_of(f, struct printer_dev, function);
@@ -1162,7 +1162,7 @@ static struct usb_configuration printer_cfg_driver = {
 	.bmAttributes		= USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
 };
 
-static int __init printer_bind_config(struct usb_configuration *c)
+static int printer_bind_config(struct usb_configuration *c)
 {
 	struct usb_gadget	*gadget = c->cdev->gadget;
 	struct printer_dev	*dev;
@@ -1284,7 +1284,7 @@ static int printer_unbind(struct usb_composite_dev *cdev)
 	return 0;
 }
 
-static int __init printer_bind(struct usb_composite_dev *cdev)
+static int printer_bind(struct usb_composite_dev *cdev)
 {
 	int ret;
 
diff --git a/drivers/usb/gadget/legacy/serial.c b/drivers/usb/gadget/legacy/serial.c
index 1f5f978..812780f 100644
--- a/drivers/usb/gadget/legacy/serial.c
+++ b/drivers/usb/gadget/legacy/serial.c
@@ -174,7 +174,7 @@ out:
 	return ret;
 }
 
-static int __init gs_bind(struct usb_composite_dev *cdev)
+static int gs_bind(struct usb_composite_dev *cdev)
 {
 	int			status;
 
diff --git a/drivers/usb/gadget/legacy/webcam.c b/drivers/usb/gadget/legacy/webcam.c
index 04a3da2..d200ab4 100644
--- a/drivers/usb/gadget/legacy/webcam.c
+++ b/drivers/usb/gadget/legacy/webcam.c
@@ -334,7 +334,7 @@ static const struct uvc_descriptor_header * const uvc_ss_streaming_cls[] = {
  * USB configuration
  */
 
-static int __init
+static int
 webcam_config_bind(struct usb_configuration *c)
 {
 	int status = 0;
@@ -368,7 +368,7 @@ webcam_unbind(struct usb_composite_dev *cdev)
 	return 0;
 }
 
-static int __init
+static int
 webcam_bind(struct usb_composite_dev *cdev)
 {
 	struct f_uvc_opts *uvc_opts;
diff --git a/drivers/usb/gadget/legacy/zero.c b/drivers/usb/gadget/legacy/zero.c
index ff97ac9..f805bc2 100644
--- a/drivers/usb/gadget/legacy/zero.c
+++ b/drivers/usb/gadget/legacy/zero.c
@@ -289,7 +289,7 @@ static struct usb_function_instance *func_inst_lb;
 module_param_named(qlen, gzero_options.qlen, uint, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(qlen, "depth of loopback queue");
 
-static int __init zero_bind(struct usb_composite_dev *cdev)
+static int zero_bind(struct usb_composite_dev *cdev)
 {
 	struct f_ss_opts	*ss_opts;
 	struct f_lb_opts	*lb_opts;
-- 
1.9.1

Re: [PATCH v2 0/2] usb/gadget: independent registration of gadgets and gadget

[Alan Stern]

On Mon, 16 Feb 2015, Ruslan Bilovol wrote:

> This patchset adds independent registration of gadgets
> and gadget drivers to udc-core. This is very useful for
> built-in modules into kernel case since it's possible
> situation that gadget driver is probing at a time
> when no gadgets are registered in udc-core.
> In this case instead of silently failing without
> of any attempt to recover, with independent registration
> of gadgets and gadget drivers there is no matter
> in which order gadgets and gadget drivers are
> probed/registered.
> 
> This patch has side-effect on gadget drivers that had
> __init/__exit attributes on some paths like bind/unbind
> and (since bind/unbind may happen at any time) should
> not use them now. This is covered by second patch
> (please let me know if I need to break it into separate
> patches for each gadget driver)

The two patches should be in the opposite order.  Otherwise someone
might apply the first patch but not the second, and then the gadget
drivers would crash when their bind/unbind routines were called at the 
wrong time.

Alan Stern

Re: [PATCH v2 0/2] usb/gadget: independent registration of gadgets and gadget

[Ruslan Bilovol]

Hi Alan,

On Mon, Feb 16, 2015 at 1:04 AM, Alan Stern <stern@rowland.harvard.edu> wrote:
> On Mon, 16 Feb 2015, Ruslan Bilovol wrote:
>
>> This patchset adds independent registration of gadgets
>> and gadget drivers to udc-core. This is very useful for
>> built-in modules into kernel case since it's possible
>> situation that gadget driver is probing at a time
>> when no gadgets are registered in udc-core.
>> In this case instead of silently failing without
>> of any attempt to recover, with independent registration
>> of gadgets and gadget drivers there is no matter
>> in which order gadgets and gadget drivers are
>> probed/registered.
>>
>> This patch has side-effect on gadget drivers that had
>> __init/__exit attributes on some paths like bind/unbind
>> and (since bind/unbind may happen at any time) should
>> not use them now. This is covered by second patch
>> (please let me know if I need to break it into separate
>> patches for each gadget driver)
>
> The two patches should be in the opposite order.  Otherwise someone
> might apply the first patch but not the second, and then the gadget
> drivers would crash when their bind/unbind routines were called at the
> wrong time.

Agree, this will be done in v3 patch set.

Best regards,
Ruslan

>
> Alan Stern
>