From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752733Ab3KKECz (ORCPT ); Sun, 10 Nov 2013 23:02:55 -0500 Received: from mga11.intel.com ([192.55.52.93]:20242 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752558Ab3KKECt (ORCPT ); Sun, 10 Nov 2013 23:02:49 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,675,1378882800"; d="scan'208";a="431093612" Message-ID: <5280567C.2060004@linux.intel.com> Date: Sun, 10 Nov 2013 20:01:00 -0800 From: David Cohen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20131005 Icedove/17.0.9 MIME-Version: 1.0 To: Michal Nazarewicz CC: Alan Stern , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Michal Nazarewicz Subject: Re: [PATCH 2/2] check quirk to pad epout buf size when not aligned to maxpacketsize References: <1384102237-19784-1-git-send-email-mpn@google.com> <1384102237-19784-2-git-send-email-mpn@google.com> In-Reply-To: <1384102237-19784-2-git-send-email-mpn@google.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Michal, On 11/10/2013 08:50 AM, Michal Nazarewicz wrote: > From: Michal Nazarewicz > > Check gadget.quirk_ep_out_aligned_size to decide if buffer size requires > to be aligned to maxpacketsize of an out endpoint. ffs_epfile_io() needs > to pad epout buffer to match above condition if quirk is found. > > Signed-off-by: Michal Nazarewicz > --- > I'm wondering whether the len should be aligned down rather then up. > This would have it's own problems, but maybe better then > a possibility of silently dropping data. > > drivers/usb/gadget/f_fs.c | 21 ++++++++++++++++++--- > 1 file changed, 18 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c > index f875f26..ea0b8ba 100644 > --- a/drivers/usb/gadget/f_fs.c > +++ b/drivers/usb/gadget/f_fs.c > @@ -753,8 +753,9 @@ static ssize_t ffs_epfile_io(struct file *file, > char __user *buf, size_t len, int read) > { > struct ffs_epfile *epfile = file->private_data; > + struct usb_gadget *gadget = epfile->ffs->gadget; > struct ffs_ep *ep; > - ssize_t ret; > + ssize_t ret, data_len; > char *data; > int halt; > > @@ -787,6 +788,13 @@ static ssize_t ffs_epfile_io(struct file *file, > > /* Allocate & copy */ > if (!halt) { > + /* > + * Controller requires buffer size to be aligned to > + * maxpacketsize of an out endpoint. > + */ > + data_len = read && gadget->quirk_ep_out_aligned_size ? > + usb_ep_align_maxpacketsize(ep->ep, len) : len; > + > data = kmalloc(len, GFP_KERNEL); Shouldn't this kmalloc() allocate 'data_len' bytes, instead of 'len'? Br, David