On Tue, Oct 07 2014, David Cohen <david.a.co...@linux.intel.com> wrote:
> The commit '2e4c7553cd usb: gadget: f_fs: add aio support' broke the
> quirk implemented to align buffer size to maxpacketsize on out endpoint.
> As result, functionfs does not work on Intel platforms using dwc3 driver
> (i.e. Bay Trail and Merrifield). This patch fixes the issue.
>
> This code is based on a previous Qiuxu's patch.
>
> Signed-off-by: David Cohen <david.a.co...@linux.intel.com>
> Signed-off-by: Qiuxu Zhuo <qiuxu.z...@intel.com>
Acked-by: Michal Nazarewicz <min...@mina86.com>
> ---
>
> Hi,
>
> Since this is a feature that worked in past, this patch is meant for 3.17
> kernel. If/when we pass review and accept it on 3.17, I'll send a version for
> stable 3.16 kernel too. It is not required for 3.14, since the regression came
> later.
>
> Br, David Cohen
>
> ---
> drivers/usb/gadget/function/f_fs.c | 21 ++++++++++++++++-----
> 1 file changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_fs.c
> b/drivers/usb/gadget/function/f_fs.c
> index 0dc3552d1360..6e2b8063b170 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -648,15 +648,26 @@ static void ffs_user_copy_worker(struct work_struct
> *work)
> if (io_data->read && ret > 0) {
> int i;
> size_t pos = 0;
> +
> + /*
> + * Since req->length may be bigger than io_data->len (after
> + * being rounded up to maxpacketsize), we may end up with more
> + * data then user space has space for.
> + */
> + ret = min_t(int, ret, io_data->len);
> +
> use_mm(io_data->mm);
> for (i = 0; i < io_data->nr_segs; i++) {
> + size_t len = min_t(size_t, ret - pos,
> + io_data->iovec[i].iov_len);
> + if (!len)
> + break;
> if (unlikely(copy_to_user(io_data->iovec[i].iov_base,
> - &io_data->buf[pos],
> - io_data->iovec[i].iov_len))) {
> + &io_data->buf[pos], len))) {
> ret = -EFAULT;
> break;
> }
> - pos += io_data->iovec[i].iov_len;
> + pos += len;
> }
> unuse_mm(io_data->mm);
> }
> @@ -794,7 +805,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct
> ffs_io_data *io_data)
> goto error_lock;
>
> req->buf = data;
> - req->length = io_data->len;
> + req->length = data_len;
>
> io_data->buf = data;
> io_data->ep = ep->ep;
> @@ -816,7 +827,7 @@ static ssize_t ffs_epfile_io(struct file *file, struct
> ffs_io_data *io_data)
>
> req = ep->req;
> req->buf = data;
> - req->length = io_data->len;
> + req->length = data_len;
>
> req->context = &done;
> req->complete = ffs_epfile_io_complete;
> --
> 2.1.0
>
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +--<m...@google.com>--<xmpp:min...@jabber.org>--ooO--(_)--Ooo--
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