fastboot: OUT transaction length must be aligned to wMaxPacketSize

OUT transactions must be aligned to wMaxPacketSize for each transfer,
or else transfer will not complete successfully. This patch modifies
rx_bytes_expected to return a transfer length that is aligned to
wMaxPacketSize.

Note that the value of wMaxPacketSize and ep->maxpacket may not be
the same value, and it is the value of wMaxPacketSize that should be
used for alignment. wMaxPacketSize is passed depending on the speed of
connection.

Signed-off-by: Dileep Katta <dileep.katta@linaro.org>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>

diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index 61389066c1f7c379138ecf47a96828209444f236..fd9fc8af6ec153347b5491b23f955d69cfea45b8 100644 (file)
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -55,6 +55,7 @@ static inline struct f_fastboot *func_to_fastboot(struct usb_function *f)
 static struct f_fastboot *fastboot_func;
 static unsigned int download_size;
 static unsigned int download_bytes;
+static bool is_high_speed;
 
 static struct usb_endpoint_descriptor fs_ep_in = {
        .bLength            = USB_DT_ENDPOINT_SIZE,
@@ -219,10 +220,13 @@ static int fastboot_set_alt(struct usb_function *f,
              __func__, f->name, interface, alt);
 
        /* make sure we don't enable the ep twice */
-       if (gadget->speed == USB_SPEED_HIGH)
+       if (gadget->speed == USB_SPEED_HIGH) {
                ret = usb_ep_enable(f_fb->out_ep, &hs_ep_out);
-       else
+               is_high_speed = true;
+       } else {
                ret = usb_ep_enable(f_fb->out_ep, &fs_ep_out);
+               is_high_speed = false;
+       }
        if (ret) {
                puts("failed to enable out ep\n");
                return ret;
@@ -370,13 +374,20 @@ static void cb_getvar(struct usb_ep *ep, struct usb_request *req)
        fastboot_tx_write_str(response);
 }
 
-static unsigned int rx_bytes_expected(void)
+static unsigned int rx_bytes_expected(unsigned int maxpacket)
 {
        int rx_remain = download_size - download_bytes;
+       int rem = 0;
        if (rx_remain < 0)
                return 0;
        if (rx_remain > EP_BUFFER_SIZE)
                return EP_BUFFER_SIZE;
+       if (rx_remain < maxpacket) {
+               rx_remain = maxpacket;
+       } else if (rx_remain % maxpacket != 0) {
+               rem = rx_remain % maxpacket;
+               rx_remain = rx_remain + (maxpacket - rem);
+       }
        return rx_remain;
 }
 
@@ -388,6 +399,7 @@ static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
        const unsigned char *buffer = req->buf;
        unsigned int buffer_size = req->actual;
        unsigned int pre_dot_num, now_dot_num;
+       unsigned int max;
 
        if (req->status != 0) {
                printf("Bad status: %d\n", req->status);
@@ -425,7 +437,9 @@ static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
 
                printf("\ndownloading of %d bytes finished\n", download_bytes);
        } else {
-               req->length = rx_bytes_expected();
+               max = is_high_speed ? hs_ep_out.wMaxPacketSize :
+                               fs_ep_out.wMaxPacketSize;
+               req->length = rx_bytes_expected(max);
                if (req->length < ep->maxpacket)
                        req->length = ep->maxpacket;
        }
@@ -438,6 +452,7 @@ static void cb_download(struct usb_ep *ep, struct usb_request *req)
 {
        char *cmd = req->buf;
        char response[RESPONSE_LEN];
+       unsigned int max;
 
        strsep(&cmd, ":");
        download_size = simple_strtoul(cmd, NULL, 16);
@@ -453,7 +468,9 @@ static void cb_download(struct usb_ep *ep, struct usb_request *req)
        } else {
                sprintf(response, "DATA%08x", download_size);
                req->complete = rx_handler_dl_image;
-               req->length = rx_bytes_expected();
+               max = is_high_speed ? hs_ep_out.wMaxPacketSize :
+                       fs_ep_out.wMaxPacketSize;
+               req->length = rx_bytes_expected(max);
                if (req->length < ep->maxpacket)
                        req->length = ep->maxpacket;
        }