Sorry to sent a wrong set of patches. Please ignore it. Best Regards, Neil Zhang > -----Original Message----- > From: Neil Zhang [mailto:zhangwm@xxxxxxxxxxx] > Sent: 2012年5月3日 14:04 > To: haojian.zhuang@xxxxxxxxx; eric.y.miao@xxxxxxxxx > Cc: Chao Xie; linux-usb@xxxxxxxxxxxxxxx; Neil Zhang > Subject: [PATCH] usb: gadget: mv_udc: fix potential register access > when clock off > > The Android gadget has sysfs interface to configure usb gadget. > And it may access udc driver when there is no cable attached. > That is too say, the udc controller may in clock off status. > It will cause system hang when access udc controller's register at this > time. > > Change-Id: Ib8783b725f5f57323499d23bc891c6f9a07b5e8d > Signed-off-by: Neil Zhang <zhangwm@xxxxxxxxxxx> > --- > drivers/usb/gadget/mv_udc_core.c | 12 +++++++++++- > 1 files changed, 11 insertions(+), 1 deletions(-) > > diff --git a/drivers/usb/gadget/mv_udc_core.c > b/drivers/usb/gadget/mv_udc_core.c > index 771ef45..067cf65 100644 > --- a/drivers/usb/gadget/mv_udc_core.c > +++ b/drivers/usb/gadget/mv_udc_core.c > @@ -594,6 +594,9 @@ static int mv_ep_disable(struct usb_ep *_ep) > > udc = ep->udc; > > + if (!udc->active) > + return 0; > + > /* Get the endpoint queue head address */ > dqh = ep->dqh; > > @@ -839,6 +842,9 @@ static int mv_ep_dequeue(struct usb_ep *_ep, struct > usb_request *_req) > if (!_ep || !_req) > return -EINVAL; > > + if (!udc->active) > + return 0; > + > spin_lock_irqsave(&ep->udc->lock, flags); > stopped = ep->stopped; > > @@ -2333,6 +2339,11 @@ usb_reg_show(struct device *dev, struct > device_attribute *attr, char *buf) > return -1; > } > > + if (!udc->active) { > + ret = sprintf(buf, "The controller is clock off now.\n"); > + return ret; > + } > + > ret = sprintf(buf, "usbcmd: 0x%x\n", > readl(&udc->op_regs->usbcmd)); > ret += sprintf(buf + ret, "usbsts: 0x%x\n", > @@ -2365,7 +2376,6 @@ usb_reg_show(struct device *dev, struct > device_attribute *attr, char *buf) > for (i = 0; i < 16; i++) > ret += sprintf(buf + ret, "epctrlx[%d]: 0x%x\n", > i, readl(&udc->op_regs->epctrlx[i])); > - > return ret; > } > > -- > 1.7.4.1 ?韬{.n?????%??檩??w?{.n???{炳???骅w* jg????????G??⒏ ⒎?:+v???????? ????＂??????
