Hi, On Monday 22 October 2012 03:33:19 Li Yang-R58472 wrote: > On Saturday, October 20, 2012 1:37 AM Felipe Balbi wrote: > > On Fri, Oct 19, 2012 at 06:19:26PM +0100, Simon Haggett wrote: > > > Some gadget drivers may attempt to dequeue requests for an endpoint > > > that has already been disabled. For example, in the UVC gadget driver, > > > uvc_function_set_alt() will call usb_ep_disable() when alt setting 0 > > > is selected. When the userspace application subsequently issues the > > > VIDIOC_STREAMOFF ioctl, uvc_video_enable() invokes usb_ep_dequeue() to > > > > ensure that all requests have been cancelled. > > > > bug is on uvc gadget, then. Laurent ? We've discussed this topic a couple of months before. I believe that's not a bug. http://68.183.106.108/lists/linux-usb/msg68869.html > > Also, fsl should be removed from the tree, I'm trying to persuade iMX > > folks to use drivers/usb/chipidea instead. > > Besides the iMX usage, the driver is also being used by many Freescale > PowerPC/Coldfire SoCs. I agree that it's ideal to move to a common driver. > But it is a large task to make the chipidea driver works for all the > hardware that fsl_udc had supported and been tested on. > > > > For the Freescale High Speed Dual-Role USB controller, > > > fsl_ep_dequeue() provides the implementation of usb_ep_dequeue(). If > > > this is called for a disabled endpoint, a kernel oops will occur when > > > > the ep->ep.desc field is dereferenced (by ep_index()). > > > > > fsl_ep_disable() sets this field to NULL, as well as deleting all > > > pending requests for the endpoint. > > > > > > This patch adds an additional check to fsl_ep_dequeue() to ensure that > > > the endpoint has not already been disabled before attempting to dequeue > > > > requests. > > > > > Signed-off-by: Simon Haggett <simon.haggett@xxxxxxxxxxx> > > > --- > > > > > > drivers/usb/gadget/fsl_udc_core.c | 5 ++++- > > > 1 files changed, 4 insertions(+), 1 deletions(-) > > > > > > diff --git a/drivers/usb/gadget/fsl_udc_core.c > > > b/drivers/usb/gadget/fsl_udc_core.c > > > index 6ae70cb..acd513b 100644 > > > --- a/drivers/usb/gadget/fsl_udc_core.c > > > +++ b/drivers/usb/gadget/fsl_udc_core.c > > > @@ -955,7 +955,10 @@ static int fsl_ep_dequeue(struct usb_ep *_ep, > > struct usb_request *_req) > > > > > int ep_num, stopped, ret = 0; > > > u32 epctrl; > > > > > > - if (!_ep || !_req) > > > + /* Ensure that the ep and request are valid, and the ep is not > > > + * disabled > > > + */ > > > + if (!_ep || !_req || !ep->ep.desc) > > > return -EINVAL; Shouldn't that last check be done with a lock taken ? > > > spin_lock_irqsave(&ep->udc->lock, flags); -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
