Re: [PATCH 2/2] gadget: Support for the usb charger framework

[Peter Chen <peter.chen@freescale.com>]

On Thu, Aug 06, 2015 at 03:03:49PM +0800, Baolin Wang wrote:
> The usb charger framework is based on usb gadget, and each usb gadget
> can be one usb charger to set the current limitation.
> 
> This patch adds a notifier mechanism for usb charger to report to usb
> charger when the usb gadget state is changed.
> 
> Also we introduce a callback 'get_charger_type' which will implemented
> by user for usb gadget operations to get the usb charger type.
> 
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> ---
>  drivers/usb/gadget/udc/udc-core.c |   41 +++++++++++++++++++++++++++++++++++++
>  include/linux/usb/gadget.h        |   20 ++++++++++++++++++
>  2 files changed, 61 insertions(+)
> 
> diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
> index d69c355..d5368088 100644
> --- a/drivers/usb/gadget/udc/udc-core.c
> +++ b/drivers/usb/gadget/udc/udc-core.c
> @@ -28,6 +28,7 @@
>  #include <linux/usb/ch9.h>
>  #include <linux/usb/gadget.h>
>  #include <linux/usb.h>
> +#include <linux/usb/usb_charger.h>
>  
>  /**
>   * struct usb_udc - describes one usb device controller
> @@ -127,12 +128,45 @@ void usb_gadget_giveback_request(struct usb_ep *ep,
>  }
>  EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
>  
> +int usb_gadget_register_notify(struct usb_gadget *gadget,
> +			       struct notifier_block *nb)
> +{
> +	unsigned long flags;
> +	int ret;
> +
> +	spin_lock_irqsave(&gadget->lock, flags);

I find you use so many spin_lock_irqsave, any reasons for that?
Why mutex_lock can't be used?

-- 

Best Regards,
Peter Chen