[PATCH v9 REBASE 6/9] USB: notify phy when root hub port connect change

[Alan Stern]

On Tue, 10 Jul 2012, Richard Zhao wrote:

> On Sat, Jul 07, 2012 at 10:56:45PM +0800, Richard Zhao wrote:
> > Phy may need to change settings when port connect change.
> > 
> > Signed-off-by: Richard Zhao <richard.zhao at freescale.com>
> > Tested-by: Subodh Nijsure <snijsure at grid-net.com>
> > ---
> >  drivers/usb/core/hub.c |    8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> > index 4cc8dc9..2ba9d84 100644
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -20,6 +20,7 @@
> >  #include <linux/usb.h>
> >  #include <linux/usbdevice_fs.h>
> >  #include <linux/usb/hcd.h>
> > +#include <linux/usb/otg.h>
> >  #include <linux/usb/quirks.h>
> >  #include <linux/kthread.h>
> >  #include <linux/mutex.h>
> > @@ -4037,6 +4038,13 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
> >  		}
> >  	}
> >  
> > +	if (unlikely(hcd->phy && !hdev->parent)) {
> > +		if (portstatus & USB_PORT_STAT_CONNECTION)
> > +			usb_phy_notify_connect(hcd->phy, port1);
> > +		else
> > +			usb_phy_notify_disconnect(hcd->phy, port1);
> There's another issue. When hcd is removed, notify disconnect is not
> called. Is it ok, if I remove the above two line and add below patch:

You should keep those two lines, since it's possible for a disconnect
to occur without usb_disconnect() being called.  This happens when a
device fails to enumerate.

> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -1924,6 +1924,11 @@ void usb_disconnect(struct usb_device **pdev)
>  	 */
>  	device_del(&udev->dev);
>  
> +	if (udev->parent && !udev->parent->parent) {
> +		struct usb_hcd *hcd = bus_to_hcd(udev->bus);
> +		usb_phy_notify_disconnect(hcd->phy, udev->portnum);
> +	}

You might not want to add this.  usb_disconnect() can get called in 
situations where the device remains physically connected (if the 
firmware changes during a reset, for example).

If you want to notify the phy when the root hub is removed, there are 
better places to do it.  One possibility is in hub_quiesce(), another 
is in usb_remove_hcd().

Alan Stern