> -----Original Message-----
> From: John Youn [mailto:[email protected]]
> Sent: Friday, September 18, 2015 5:03 AM
> To: Kaukab, Yousaf; [email protected]; [email protected];
> [email protected]
> Cc: Herrero, Gregory; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]
> Subject: Re: [PATCH v1 27/32] usb: dwc2: gadget: kill ep0 requests before
> reinitializing core
>
> On 9/9/2015 3:21 AM, Mian Yousaf Kaukab wrote:
> > Make sure there are no requests pending on ep0 before reinitializing
> > core. Otherwise, dwc2_hsotg_enqueue_setup will fail afterwards.
> >
> > Signed-off-by: Mian Yousaf Kaukab <[email protected]>
> > Tested-by: Robert Baldyga <[email protected]>
> > ---
> > drivers/usb/dwc2/gadget.c | 8 +++-----
> > 1 file changed, 3 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> > index c7da6b7..a6a1a6a 100644
> > --- a/drivers/usb/dwc2/gadget.c
> > +++ b/drivers/usb/dwc2/gadget.c
> > @@ -2287,6 +2287,9 @@ void dwc2_hsotg_core_init_disconnected(struct
> > dwc2_hsotg *hsotg, {
> > u32 val;
> >
> > + /* Kill any ep0 requests as controller will be reinitialized */
> > + kill_all_requests(hsotg, hsotg->eps_out[0], -ECONNRESET);
> > +
>
> I am seeing this hang when I start off as a B-device, then plug in an A-cable
> with no device attached on the other end. Then unplug it.
>
> I haven't verified but it is probably due to the
> dwc2_hsotg_complete_request() (called from kill_all_requests) expecting lock
> to be held. But this is not locked when called from
> dwc2_conn_id_status_change().
You are spot on. dwc2_conn_id_status_change() is the only place where
dwc2_hsotg_core_init_disconnected() is called without locks. I will add
following
change to " usb: dwc2: gadget: kill ep0 requests before reinitializing core"
patch.
@@ -1386,7 +1387,9 @@ static void dwc2_conn_id_status_change(struct work_struct
*work)
hsotg->op_state = OTG_STATE_B_PERIPHERAL;
dwc2_core_init(hsotg, false, -1);
dwc2_enable_global_interrupts(hsotg);
+ spin_lock(&hsotg->lock);
dwc2_hsotg_core_init_disconnected(hsotg, false);
+ spin_unlock(&hsotg->lock);
dwc2_hsotg_core_connect(hsotg);
>
> John
BR,
Yousaf
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
