Commit 04145a03 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

USB: UDC: Implement udc_async_callbacks in dummy-hcd 



This patch adds a udc_async_callbacks handler to the dummy-hcd UDC
driver, which will prevent a theoretical race during gadget unbinding.

The implementation is simple, since dummy-hcd already has a flag to
keep track of whether emulated IRQs are enabled.  All the handler has
to do is store the enable value in the flag, and avoid setting the
flag prematurely.

Acked-by: default avatarFelipe Balbi <balbi@kernel.org>
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20210520202152.GD1216852@rowland.harvard.edu


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7dc0c55e

drivers/usb/gadget/udc/dummy_hcd.c

+10 −1
Original line number Diff line number Diff line
@@ -934,6 +934,15 @@ static void dummy_udc_set_speed(struct usb_gadget *_gadget, 
	dummy_udc_update_ep0(dum);

}



static void dummy_udc_async_callbacks(struct usb_gadget *_gadget, bool enable)

{

	struct dummy	*dum = gadget_dev_to_dummy(&_gadget->dev);



	spin_lock_irq(&dum->lock);

	dum->ints_enabled = enable;

	spin_unlock_irq(&dum->lock);

}



static int dummy_udc_start(struct usb_gadget *g,

		struct usb_gadget_driver *driver);

static int dummy_udc_stop(struct usb_gadget *g);
@@ -946,6 +955,7 @@ static const struct usb_gadget_ops dummy_ops = { 
	.udc_start	= dummy_udc_start,

	.udc_stop	= dummy_udc_stop,

	.udc_set_speed	= dummy_udc_set_speed,

	.udc_async_callbacks = dummy_udc_async_callbacks,

};



/*-------------------------------------------------------------------------*/
@@ -1005,7 +1015,6 @@ static int dummy_udc_start(struct usb_gadget *g, 
	spin_lock_irq(&dum->lock);

	dum->devstatus = 0;

	dum->driver = driver;

	dum->ints_enabled = 1;

	spin_unlock_irq(&dum->lock);



	return 0;