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

On Mon, May 13, 2013 at 7:23 PM, Vivek Gautam gautam.vivek@samsung.comwrote:

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@samsung.com

Signed-off-by: Vivek Gautam gautam.vivek@samsung.com Cc: Lukasz Majewski l.majewski@samsung.com Cc: Piotr Wilczek p.wilczek@samsung.com Cc: Kyungmin Park kyungmin.park@samsung.com Cc: Lukasz Dalek luk0104@gmail.com Cc: Marek Vasut marex@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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