[U-Boot] [PATCH 2/2] usb: gadget: Use unaligned access for wMaxPacketSize

[Kyungmin Park]

On Mon, May 13, 2013 at 7:23 PM, Vivek Gautam <gautam.vivek at samsung.com>wrote:

> Use get_unaligned() while fetching wMaxPacketSize to avoid
> voilating any alignment rules.
>

It's another story, can we get performance gain with unaligned access
feature? In case of kernel, we got some gains.

Anyway, good job!

Acked-by: Kyungmin Park <kyungmin.park at samsung.com>

>
> Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
> Cc: Lukasz Majewski <l.majewski at samsung.com>
> Cc: Piotr Wilczek <p.wilczek at samsung.com>
> Cc: Kyungmin Park <kyungmin.park at samsung.com>
> Cc: Lukasz Dalek <luk0104 at gmail.com>
> Cc: Marek Vasut <marex at denx.de>
> ---
>
> Just did a build test on u-boot-usb/master branch.
> Need to be tested further.
>
> Based on u-boot-usb/next.
>
>  drivers/usb/gadget/f_mass_storage.c |    3 ++-
>  drivers/usb/gadget/pxa25x_udc.c     |   13 +++++++------
>  2 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/gadget/f_mass_storage.c
> b/drivers/usb/gadget/f_mass_storage.c
> index c28866f..45bc132 100644
> --- a/drivers/usb/gadget/f_mass_storage.c
> +++ b/drivers/usb/gadget/f_mass_storage.c
> @@ -2261,7 +2261,8 @@ reset:
>         if (rc)
>                 goto reset;
>         fsg->bulk_out_enabled = 1;
> -       common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
> +       common->bulk_out_maxpacket =
> +
> le16_to_cpu(get_unaligned(&d->wMaxPacketSize));
>         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
>
>         /* Allocate the requests */
> diff --git a/drivers/usb/gadget/pxa25x_udc.c
> b/drivers/usb/gadget/pxa25x_udc.c
> index 9ce98f0..085503d 100644
> --- a/drivers/usb/gadget/pxa25x_udc.c
> +++ b/drivers/usb/gadget/pxa25x_udc.c
> @@ -314,7 +314,8 @@ static int pxa25x_ep_enable(struct usb_ep *_ep,
>         if (!_ep || !desc || ep->desc || _ep->name == ep0name
>                         || desc->bDescriptorType != USB_DT_ENDPOINT
>                         || ep->bEndpointAddress != desc->bEndpointAddress
> -                       || ep->fifo_size <
> le16_to_cpu(desc->wMaxPacketSize)) {
> +                       || ep->fifo_size <
> +
>  le16_to_cpu(get_unaligned(&desc->wMaxPacketSize))) {
>                 printf("%s, bad ep or descriptor\n", __func__);
>                 return -EINVAL;
>         }
> @@ -329,9 +330,9 @@ static int pxa25x_ep_enable(struct usb_ep *_ep,
>
>         /* hardware _could_ do smaller, but driver doesn't */
>         if ((desc->bmAttributes == USB_ENDPOINT_XFER_BULK
> -                               && le16_to_cpu(desc->wMaxPacketSize)
> +                       &&
> le16_to_cpu(get_unaligned(&desc->wMaxPacketSize))
>                                                 != BULK_FIFO_SIZE)
> -                       || !desc->wMaxPacketSize) {
> +                       || !get_unaligned(&desc->wMaxPacketSize)) {
>                 printf("%s, bad %s maxpacket\n", __func__, _ep->name);
>                 return -ERANGE;
>         }
> @@ -345,7 +346,7 @@ static int pxa25x_ep_enable(struct usb_ep *_ep,
>         ep->desc = desc;
>         ep->stopped = 0;
>         ep->pio_irqs = 0;
> -       ep->ep.maxpacket = le16_to_cpu(desc->wMaxPacketSize);
> +       ep->ep.maxpacket =
> le16_to_cpu(get_unaligned(&desc->wMaxPacketSize));
>
>         /* flush fifo (mostly for OUT buffers) */
>         pxa25x_ep_fifo_flush(_ep);
> @@ -485,7 +486,7 @@ write_fifo(struct pxa25x_ep *ep, struct pxa25x_request
> *req)
>  {
>         unsigned max;
>
> -       max = le16_to_cpu(ep->desc->wMaxPacketSize);
> +       max = le16_to_cpu(get_unaligned(&ep->desc->wMaxPacketSize));
>         do {
>                 unsigned count;
>                 int is_last, is_short;
> @@ -766,7 +767,7 @@ pxa25x_ep_queue(struct usb_ep *_ep, struct usb_request
> *_req, gfp_t gfp_flags)
>          */
>         if (unlikely(ep->bmAttributes == USB_ENDPOINT_XFER_ISOC
>                         && req->req.length >
> -                       le16_to_cpu(ep->desc->wMaxPacketSize)))
> +
> le16_to_cpu(get_unaligned(&ep->desc->wMaxPacketSize))))
>                 return -EMSGSIZE;
>
>         debug_cond(NOISY, "%s queue req %p, len %d buf %p\n",
> --
> 1.7.6.5
>
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