diff mbox series

[v1,2/2] usb: gadget: udc: core: Prevent redundant calls to pullup

Message ID 20230405093133.1858140-2-badhri@google.com
State New
Headers
Series [v1,1/2] usb: gadget: udc: core: Invoke usb_gadget_connect only when started |

Commit Message

Badhri Jagan Sridharan April 5, 2023, 9:31 a.m. UTC 
  usb_gadget_connect calls gadget->ops->pullup without
checking whether gadget->connected was previously set.
Make this symmetric to usb_gadget_disconnect by returning
early if gadget->connected is already set.

Cc: stable@vger.kernel.org

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Fixes: 5a1da544e572 ("usb: gadget: core: do not try to disconnect gadget if it is not connected")
---
 drivers/usb/gadget/udc/core.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Greg KH April 5, 2023, 5:15 p.m. UTC | #1 
On Wed, Apr 05, 2023 at 09:31:33AM +0000, Badhri Jagan Sridharan wrote:
> usb_gadget_connect calls gadget->ops->pullup without
> checking whether gadget->connected was previously set.
> Make this symmetric to usb_gadget_disconnect by returning
> early if gadget->connected is already set.
> 
> Cc: stable@vger.kernel.org
> 
> Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> Fixes: 5a1da544e572 ("usb: gadget: core: do not try to disconnect gadget if it is not connected")

Same changelog comment as before.

> ---
>  drivers/usb/gadget/udc/core.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> index 890f92cb6344..7eeaf7dbb350 100644
> --- a/drivers/usb/gadget/udc/core.c
> +++ b/drivers/usb/gadget/udc/core.c
> @@ -708,6 +708,9 @@ int usb_gadget_connect(struct usb_gadget *gadget)
>  		goto out;
>  	}
>  
> +	if (gadget->connected)
> +		goto out;
> +

What prevents this connected value from changing right after you check
this?

thanks,

greg k-h
Badhri Jagan Sridharan April 6, 2023, 6:35 a.m. UTC | #2 
On Wed, Apr 5, 2023 at 10:16 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Wed, Apr 05, 2023 at 09:31:33AM +0000, Badhri Jagan Sridharan wrote:
> > usb_gadget_connect calls gadget->ops->pullup without
> > checking whether gadget->connected was previously set.
> > Make this symmetric to usb_gadget_disconnect by returning
> > early if gadget->connected is already set.
> >
> > Cc: stable@vger.kernel.org
> >
> > Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> > Fixes: 5a1da544e572 ("usb: gadget: core: do not try to disconnect gadget if it is not connected")
>
> Same changelog comment as before.
Thanks for the feedback Greg ! Have fixed it in v2.

>
> > ---
> >  drivers/usb/gadget/udc/core.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> > index 890f92cb6344..7eeaf7dbb350 100644
> > --- a/drivers/usb/gadget/udc/core.c
> > +++ b/drivers/usb/gadget/udc/core.c
> > @@ -708,6 +708,9 @@ int usb_gadget_connect(struct usb_gadget *gadget)
> >               goto out;
> >       }
> >
> > +     if (gadget->connected)
> > +             goto out;
> > +
>
> What prevents this connected value from changing right after you check
> this?

Nothing in V1 :) However, in v2, the newly introduced mutex guards
gadget->connected
as well.

>
> thanks,
>
> greg k-h
diff mbox series

Patch

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 890f92cb6344..7eeaf7dbb350 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -708,6 +708,9 @@  int usb_gadget_connect(struct usb_gadget *gadget)
 		goto out;
 	}
 
+	if (gadget->connected)
+		goto out;
+
 	if (gadget->deactivated) {
 		/*
 		 * If gadget is deactivated we only save new state.