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SubjectRe: [PATCH 2/2] check quirk to pad epout buf size when not aligned to maxpacketsize
Hi Michal,

On 11/10/2013 08:50 AM, Michal Nazarewicz wrote:
> From: Michal Nazarewicz <mina86@mina86.com>
>
> 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 <mina86@mina86.com>
> ---
> 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


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