Date: Thu, 23 Apr 2015 16:45:08 +0200
From: Johan Hovold <johan@kernel.org>
To: Frans Klaver <fransklaver@gmail.com>
Cc: Johan Hovold <johan@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Felipe Balbi <balbi@ti.com>, Alan Stern <stern@rowland.harvard.edu>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Stephen Warren <swarren@wwwdotorg.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Alexandre Courbot <gnurou@gmail.com>, linux-tegra@vger.kernel.org
Subject: Re: [PATCH v2 2/3] USB: ehci-tegra: fix inefficient copy of
 unaligned buffers
Message-ID: <20150423144508.GA22193@localhost>
References: <1429798012-21916-1-git-send-email-johan@kernel.org>
 <1429798012-21916-3-git-send-email-johan@kernel.org>
 <CAH6sp9PFE_kQn5hpXaGhn6d_WTtKZUbfS-DpDRfRCKbBj9S4fQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAH6sp9PFE_kQn5hpXaGhn6d_WTtKZUbfS-DpDRfRCKbBj9S4fQ@mail.gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1518
Lines: 39

On Thu, Apr 23, 2015 at 04:31:51PM +0200, Frans Klaver wrote:
> On Thu, Apr 23, 2015 at 4:06 PM, Johan Hovold <johan@kernel.org> wrote:

> >  static void free_dma_aligned_buffer(struct urb *urb)
> >  {
> >         struct dma_aligned_buffer *temp;
> > +       size_t length;
> >
> >         if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
> >                 return;
> > @@ -311,9 +312,14 @@ static void free_dma_aligned_buffer(struct urb *urb)
> >         temp = container_of(urb->transfer_buffer,
> >                 struct dma_aligned_buffer, data);
> >
> > -       if (usb_urb_dir_in(urb))
> > -               memcpy(temp->old_xfer_buffer, temp->data,
> > -                      urb->transfer_buffer_length);
> > +       if (usb_urb_dir_in(urb)) {
> > +               if (usb_pipeisoc(urb->pipe))
> > +                       length = urb->transfer_buffer_length;
> > +               else
> > +                       length = urb->actual_length;
> > +
> > +               memcpy(temp->old_xfer_buffer, temp->data, length);
> > +       }
> >         urb->transfer_buffer = temp->old_xfer_buffer;
> >         kfree(temp->kmalloc_ptr);
> 
> Out of curiosity: any reason not to declare that length variable
> inside this new compound?

Just my style preference.

Johan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/