Re: [PATCH 07/15] Input: xpad: move the input device creation to a new function

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Thu, Oct 01, 2015 at 10:57:18PM +0200, Pavel Rojtberg wrote:
> From: "Pierre-Loup A. Griffais" <pgriffais@valvesoftware.com>
> 
> To allow us to later create / destroy the input device from the urb
> callback, we need to initialize/ deinitialize the input device from a
> separate function.  So pull that logic out now to make later patches
> more "obvious" as to what they do.
> 
> Signed-off-by: "Pierre-Loup A. Griffais" <pgriffais@valvesoftware.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Pavel Rojtberg <rojtberg@gmail.com>
> ---
>  drivers/input/joystick/xpad.c | 199 +++++++++++++++++++++++++++++++++++++----------------------------
>  1 file changed, 113 insertions(+), 86 deletions(-)
> 
> diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
> index 15da2a3..43490ea 100644
> --- a/drivers/input/joystick/xpad.c
> +++ b/drivers/input/joystick/xpad.c
> @@ -343,6 +343,7 @@ struct usb_xpad {
>  	int mapping;			/* map d-pad to buttons or to axes */
>  	int xtype;			/* type of xbox device */
>  	unsigned long pad_nr;		/* the order x360 pads were attached */
> +	const char *name;		/* name of the device */
>  };
>  
>  /*
> @@ -1044,11 +1045,101 @@ static void xpad_set_up_abs(struct input_dev *input_dev, signed short abs)
>  	}
>  }
>  
> +static int xpad_init_input(struct usb_xpad *xpad)
> +{
> +	struct input_dev *input_dev;
> +	int i, error;
> +
> +	input_dev = input_allocate_device();
> +	if (!input_dev)
> +		return -ENOMEM;
> +
> +	xpad->dev = input_dev;
> +	input_dev->name = xpad->name;
> +	input_dev->phys = xpad->phys;
> +	usb_to_input_id(xpad->udev, &input_dev->id);
> +	input_dev->dev.parent = &xpad->intf->dev;
> +
> +	input_set_drvdata(input_dev, xpad);
> +
> +	input_dev->open = xpad_open;
> +	input_dev->close = xpad_close;
> +
> +	input_dev->evbit[0] = BIT_MASK(EV_KEY);
> +
> +	if (!(xpad->mapping & MAP_STICKS_TO_NULL)) {
> +		input_dev->evbit[0] |= BIT_MASK(EV_ABS);
> +		/* set up axes */
> +		for (i = 0; xpad_abs[i] >= 0; i++)
> +			xpad_set_up_abs(input_dev, xpad_abs[i]);
> +	}
> +
> +	/* set up standard buttons */
> +	for (i = 0; xpad_common_btn[i] >= 0; i++)
> +		__set_bit(xpad_common_btn[i], input_dev->keybit);
> +
> +	/* set up model-specific ones */
> +	if (xpad->xtype == XTYPE_XBOX360 || xpad->xtype == XTYPE_XBOX360W ||
> +	    xpad->xtype == XTYPE_XBOXONE) {
> +		for (i = 0; xpad360_btn[i] >= 0; i++)
> +			__set_bit(xpad360_btn[i], input_dev->keybit);
> +	} else {
> +		for (i = 0; xpad_btn[i] >= 0; i++)
> +			__set_bit(xpad_btn[i], input_dev->keybit);
> +	}
> +
> +	if (xpad->mapping & MAP_DPAD_TO_BUTTONS) {
> +		for (i = 0; xpad_btn_pad[i] >= 0; i++)
> +			__set_bit(xpad_btn_pad[i], input_dev->keybit);
> +	}
> +	/* this should be a simple else block. However historically xbox360w
> +	 * has mapped DPAD to buttons while xbox360 did not.
> +	 * This made no sense, but now we can not just switch back and have to
> +	 * support both behaviors.
> +	 */
> +	if(!(xpad->mapping & MAP_DPAD_TO_BUTTONS) ||
> +			xpad->xtype == XTYPE_XBOX360W) {
> +		for (i = 0; xpad_abs_pad[i] >= 0; i++)
> +			xpad_set_up_abs(input_dev, xpad_abs_pad[i]);
> +	}
> +
> +	if (xpad->mapping & MAP_TRIGGERS_TO_BUTTONS) {
> +		for (i = 0; xpad_btn_triggers[i] >= 0; i++)
> +			__set_bit(xpad_btn_triggers[i], input_dev->keybit);
> +	} else {
> +		for (i = 0; xpad_abs_triggers[i] >= 0; i++)
> +			xpad_set_up_abs(input_dev, xpad_abs_triggers[i]);
> +	}
> +
> +	error = xpad_init_ff(xpad);
> +	if (error)
> +		goto fail_init_ff;
> +
> +	error = xpad_led_probe(xpad);
> +	if (error)
> +		goto fail_init_led;
> +
> +	error = input_register_device(xpad->dev);
> +	if (error)
> +		goto fail_input_register;
> +
> +	return 0;
> +
> +fail_input_register:
> +	xpad_led_disconnect(xpad);
> +
> +fail_init_led:
> +	input_ff_destroy(input_dev);
> +
> +fail_init_ff:
> +	input_free_device(input_dev);
> +	return error;
> +}
> +
>  static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id)
>  {
>  	struct usb_device *udev = interface_to_usbdev(intf);
>  	struct usb_xpad *xpad;
> -	struct input_dev *input_dev;
>  	struct usb_endpoint_descriptor *ep_irq_in;
>  	int ep_irq_in_idx;
>  	int i, error;
> @@ -1070,12 +1161,14 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
>  	}
>  
>  	xpad = kzalloc(sizeof(struct usb_xpad), GFP_KERNEL);
> -	input_dev = input_allocate_device();
> -	if (!xpad || !input_dev) {
> +	if (!xpad) {
>  		error = -ENOMEM;
>  		goto fail1;
>  	}
>  
> +	usb_make_path(udev, xpad->phys, sizeof(xpad->phys));
> +	strlcat(xpad->phys, "/input0", sizeof(xpad->phys));
> +
>  	xpad->idata = usb_alloc_coherent(udev, XPAD_PKT_LEN,
>  					 GFP_KERNEL, &xpad->idata_dma);
>  	if (!xpad->idata) {
> @@ -1093,6 +1186,7 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
>  	xpad->intf = intf;
>  	xpad->mapping = xpad_device[i].mapping;
>  	xpad->xtype = xpad_device[i].xtype;
> +	xpad->name = xpad_device[i].name;
>  
>  	if (xpad->xtype == XTYPE_UNKNOWN) {
>  		if (intf->cur_altsetting->desc.bInterfaceClass == USB_CLASS_VENDOR_SPEC) {
> @@ -1111,78 +1205,10 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
>  			xpad->mapping |= MAP_STICKS_TO_NULL;
>  	}
>  
> -	xpad->dev = input_dev;
> -	usb_make_path(udev, xpad->phys, sizeof(xpad->phys));
> -	strlcat(xpad->phys, "/input0", sizeof(xpad->phys));
> -
> -	input_dev->name = xpad_device[i].name;
> -	input_dev->phys = xpad->phys;
> -	usb_to_input_id(udev, &input_dev->id);
> -	input_dev->dev.parent = &intf->dev;
> -
> -	input_set_drvdata(input_dev, xpad);
> -
> -	input_dev->open = xpad_open;
> -	input_dev->close = xpad_close;
> -
> -	input_dev->evbit[0] = BIT_MASK(EV_KEY);
> -
> -	if (!(xpad->mapping & MAP_STICKS_TO_NULL)) {
> -		input_dev->evbit[0] |= BIT_MASK(EV_ABS);
> -		/* set up axes */
> -		for (i = 0; xpad_abs[i] >= 0; i++)
> -			xpad_set_up_abs(input_dev, xpad_abs[i]);
> -	}
> -
> -	/* set up standard buttons */
> -	for (i = 0; xpad_common_btn[i] >= 0; i++)
> -		__set_bit(xpad_common_btn[i], input_dev->keybit);
> -
> -	/* set up model-specific ones */
> -	if (xpad->xtype == XTYPE_XBOX360 || xpad->xtype == XTYPE_XBOX360W ||
> -	    xpad->xtype == XTYPE_XBOXONE) {
> -		for (i = 0; xpad360_btn[i] >= 0; i++)
> -			__set_bit(xpad360_btn[i], input_dev->keybit);
> -	} else {
> -		for (i = 0; xpad_btn[i] >= 0; i++)
> -			__set_bit(xpad_btn[i], input_dev->keybit);
> -	}
> -
> -	if (xpad->mapping & MAP_DPAD_TO_BUTTONS) {
> -		for (i = 0; xpad_btn_pad[i] >= 0; i++)
> -			__set_bit(xpad_btn_pad[i], input_dev->keybit);
> -	}
> -	/* this should be a simple else block. However historically xbox360w
> -	 * has mapped DPAD to buttons while xbox360 did not.
> -	 * This made no sense, but now we can not just switch back and have to
> -	 * support both behaviors.
> -	 */
> -	if(!(xpad->mapping & MAP_DPAD_TO_BUTTONS) ||
> -			xpad->xtype == XTYPE_XBOX360W) {
> -		for (i = 0; xpad_abs_pad[i] >= 0; i++)
> -			xpad_set_up_abs(input_dev, xpad_abs_pad[i]);
> -	}
> -
> -	if (xpad->mapping & MAP_TRIGGERS_TO_BUTTONS) {
> -		for (i = 0; xpad_btn_triggers[i] >= 0; i++)
> -			__set_bit(xpad_btn_triggers[i], input_dev->keybit);
> -	} else {
> -		for (i = 0; xpad_abs_triggers[i] >= 0; i++)
> -			xpad_set_up_abs(input_dev, xpad_abs_triggers[i]);
> -	}
> -
>  	error = xpad_init_output(intf, xpad);
>  	if (error)
>  		goto fail3;
>  
> -	error = xpad_init_ff(xpad);
> -	if (error)
> -		goto fail4;
> -
> -	error = xpad_led_probe(xpad);
> -	if (error)
> -		goto fail5;
> -
>  	/* Xbox One controller has in/out endpoints swapped. */
>  	ep_irq_in_idx = xpad->xtype == XTYPE_XBOXONE ? 1 : 0;
>  	ep_irq_in = &intf->cur_altsetting->endpoint[ep_irq_in_idx].desc;
> @@ -1194,10 +1220,6 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
>  	xpad->irq_in->transfer_dma = xpad->idata_dma;
>  	xpad->irq_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
>  
> -	error = input_register_device(xpad->dev);
> -	if (error)
> -		goto fail6;
> -
>  	usb_set_intfdata(intf, xpad);
>  
>  	if (xpad->xtype == XTYPE_XBOX360W) {
> @@ -1210,32 +1232,37 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
>  		 */
>  		xpad->irq_in->dev = xpad->udev;
>  		error = usb_submit_urb(xpad->irq_in, GFP_KERNEL);
> -		if (error)
> -			goto fail7;
> +		if (error) {
> +			usb_kill_urb(xpad->irq_in);

Why do we need to kill urb if its submission failed?

> +			goto fail4;
> +		}
>  	}
> +	xpad->pad_present = 1;
> +	error = xpad_init_input(xpad);

This is too late, at least in the context of this patch. The packets may
already be flowing.

I moved this chunk up.

> +	if (error)
> +		goto fail4;
>  
>  	return 0;
>  
> - fail7:	input_unregister_device(input_dev);
> -	input_dev = NULL;
> - fail6:	xpad_led_disconnect(xpad);
> - fail5:	if (input_dev)
> -		input_ff_destroy(input_dev);
>   fail4:	xpad_deinit_output(xpad);
>   fail3:	usb_free_urb(xpad->irq_in);
>   fail2:	usb_free_coherent(udev, XPAD_PKT_LEN, xpad->idata, xpad->idata_dma);
> - fail1:	input_free_device(input_dev);
> -	kfree(xpad);
> + fail1:	kfree(xpad);
>  	return error;
>  
>  }
>  
> +static void xpad_deinit_input(struct usb_xpad *xpad)
> +{
> +	xpad_led_disconnect(xpad);
> +	input_unregister_device(xpad->dev);
> +}
> +
>  static void xpad_disconnect(struct usb_interface *intf)
>  {
>  	struct usb_xpad *xpad = usb_get_intfdata (intf);
>  
> -	xpad_led_disconnect(xpad);
> -	input_unregister_device(xpad->dev);
> +	xpad_deinit_input(xpad);
>  	xpad_deinit_output(xpad);
>  
>  	if (xpad->xtype == XTYPE_XBOX360W) {
> -- 
> 1.9.1
> 

Thanks.

-- 
Dmitry