Re: [RFC][PATCH v2 06/13] usb: hcd: Add hcd add/remove functions for OTG use

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

On Tue, Apr 14, 2015 at 01:41:53PM +0300, Roger Quadros wrote:
> The existing usb_add/remove_hcd() functionality
> remains unchanged for non-OTG devices. For OTG
> devices they only register the HCD with the OTG core.
> 
> Introduce _usb_add/remove_hcd() for use by OTG core.
> These functions actually add/remove the HCD.

Would you please explain why additional _usb_add/remove_hcd are needed?

Peter
> 
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
>  drivers/usb/common/usb-otg.c | 14 +++++++-------
>  drivers/usb/core/hcd.c       | 24 ++++++++++++++++++++++--
>  include/linux/usb/hcd.h      |  3 +++
>  3 files changed, 32 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
> index e848e08..860e2e7 100644
> --- a/drivers/usb/common/usb-otg.c
> +++ b/drivers/usb/common/usb-otg.c
> @@ -198,18 +198,18 @@ static int usb_otg_start_host(struct otg_fsm *fsm, int on)
>  			otgd->start_host(fsm, on);
>  
>  		/* start host */
> -		usb_add_hcd(otgd->primary_hcd.hcd, otgd->primary_hcd.irqnum,
> -			    otgd->primary_hcd.irqflags);
> +		_usb_add_hcd(otgd->primary_hcd.hcd, otgd->primary_hcd.irqnum,
> +			     otgd->primary_hcd.irqflags);
>  		if (otgd->shared_hcd.hcd) {
> -			usb_add_hcd(otgd->shared_hcd.hcd,
> -				    otgd->shared_hcd.irqnum,
> -				    otgd->shared_hcd.irqflags);
> +			_usb_add_hcd(otgd->shared_hcd.hcd,
> +				     otgd->shared_hcd.irqnum,
> +				     otgd->shared_hcd.irqflags);
>  		}
>  	} else {
>  		/* stop host */
>  		if (otgd->shared_hcd.hcd)
> -			usb_remove_hcd(otgd->shared_hcd.hcd);
> -		usb_remove_hcd(otgd->primary_hcd.hcd);
> +			_usb_remove_hcd(otgd->shared_hcd.hcd);
> +		_usb_remove_hcd(otgd->primary_hcd.hcd);
>  
>  		/* OTG device operations */
>  		if (otgd->start_host)
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 45a915c..9a9c0f7 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -46,6 +46,7 @@
>  #include <linux/usb.h>
>  #include <linux/usb/hcd.h>
>  #include <linux/usb/phy.h>
> +#include <linux/usb/usb-otg.h>
>  
>  #include "usb.h"
>  
> @@ -2622,7 +2623,7 @@ static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
>   * buffers of consistent memory, register the bus, request the IRQ line,
>   * and call the driver's reset() and start() routines.
>   */
> -int usb_add_hcd(struct usb_hcd *hcd,
> +int _usb_add_hcd(struct usb_hcd *hcd,
>  		unsigned int irqnum, unsigned long irqflags)
>  {
>  	int retval;
> @@ -2827,6 +2828,17 @@ err_phy:
>  	}
>  	return retval;
>  }
> +EXPORT_SYMBOL_GPL(_usb_add_hcd);
> +
> +int usb_add_hcd(struct usb_hcd *hcd,
> +		unsigned int irqnum, unsigned long irqflags)
> +{
> +	/* If OTG device, OTG core takes care of adding HCD */
> +	if (usb_otg_register_hcd(hcd, irqnum, irqflags))
> +		return _usb_add_hcd(hcd, irqnum, irqflags);
> +
> +	return 0;
> +}
>  EXPORT_SYMBOL_GPL(usb_add_hcd);
>  
>  /**
> @@ -2837,7 +2849,7 @@ EXPORT_SYMBOL_GPL(usb_add_hcd);
>   * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
>   * invoking the HCD's stop() method.
>   */
> -void usb_remove_hcd(struct usb_hcd *hcd)
> +void _usb_remove_hcd(struct usb_hcd *hcd)
>  {
>  	struct usb_device *rhdev = hcd->self.root_hub;
>  
> @@ -2911,6 +2923,14 @@ void usb_remove_hcd(struct usb_hcd *hcd)
>  
>  	usb_put_invalidate_rhdev(hcd);
>  }
> +EXPORT_SYMBOL_GPL(_usb_remove_hcd);
> +
> +void usb_remove_hcd(struct usb_hcd *hcd)
> +{
> +	/* If OTG device, OTG core takes care of stopping HCD */
> +	if (usb_otg_unregister_hcd(hcd))
> +		_usb_remove_hcd(hcd);
> +}
>  EXPORT_SYMBOL_GPL(usb_remove_hcd);
>  
>  void
> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
> index 68b1e83..7993ae7 100644
> --- a/include/linux/usb/hcd.h
> +++ b/include/linux/usb/hcd.h
> @@ -433,7 +433,10 @@ extern void usb_put_hcd(struct usb_hcd *hcd);
>  extern int usb_hcd_is_primary_hcd(struct usb_hcd *hcd);
>  extern int usb_add_hcd(struct usb_hcd *hcd,
>  		unsigned int irqnum, unsigned long irqflags);
> +extern int _usb_add_hcd(struct usb_hcd *hcd,
> +		unsigned int irqnum, unsigned long irqflags);
>  extern void usb_remove_hcd(struct usb_hcd *hcd);
> +extern void _usb_remove_hcd(struct usb_hcd *hcd);
>  extern int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1);
>  
>  struct platform_device;
> -- 
> 2.1.0
> 

-- 

Best Regards,
Peter Chen