Re: [PATCH] usb: gadget/uvc: Remove non-required locking from 'uvc_queue_next_buffer' routine

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Mar 23, 2012 at 05:31:19PM +0800, Bhupesh SHARMA wrote:
> Hi Felipe,
> 
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > Sent: Thursday, March 22, 2012 8:11 PM
> > To: Bhupesh SHARMA
> > Cc: linux-usb@vger.kernel.org; laurent.pinchart@ideasonboard.com;
> > spear-devel; linux-media@vger.kernel.org
> > Subject: Re: [PATCH] usb: gadget/uvc: Remove non-required locking from
> > 'uvc_queue_next_buffer' routine
> > 
> > On Thu, Mar 22, 2012 at 10:20:37AM +0530, Bhupesh Sharma wrote:
> > > This patch removes the non-required spinlock acquire/release calls on
> > > 'queue_irqlock' from 'uvc_queue_next_buffer' routine.
> > >
> > > This routine is called from 'video->encode' function (which
> > translates to either
> > > 'uvc_video_encode_bulk' or 'uvc_video_encode_isoc') in 'uvc_video.c'.
> > > As, the 'video->encode' routines are called with 'queue_irqlock'
> > already held,
> > > so acquiring a 'queue_irqlock' again in 'uvc_queue_next_buffer'
> > routine causes
> > > a spin lock recursion.
> > >
> > > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
> > > Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > ---
> > >  drivers/usb/gadget/uvc_queue.c |    4 +---
> > >  1 files changed, 1 insertions(+), 3 deletions(-)
> > 
> > Please use scripts/get_maintainer.pl to determine who to send this to
> > (hint, it's not me...)
> > 
> 
> Can you please pick this USB webcam gadget/peripheral specific patch
> in your tree?

You didn't put the patch in your request.  Hint, just resend it with the
proper information, digging patches out of old email threads is a major
pain when you are dealing with the patch load kernel maintainers do.

thanks,

greg k-h