A function is allowed to return NAKs during the DATA stage to control
data flow control. NAKs during the STATUS stage signal the function
is still processing the request.

Signed-off-by: Stefan Brüns <[email protected]>
---
 drivers/usb/host/dwc2.c | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index 5ef6deb..db3acd4 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -892,8 +892,8 @@ static int _submit_control_msg(struct dwc2_priv *priv, 
struct usb_device *dev,
 {
        int devnum = usb_pipedevice(pipe);
        int pid, ret, act_len;
-       /* For CONTROL endpoint pid should start with DATA1 */
        int status_direction;
+       unsigned long timeout;
 
        if (devnum == priv->root_hub_devnum) {
                dev->status = 0;
@@ -907,26 +907,37 @@ static int _submit_control_msg(struct dwc2_priv *priv, 
struct usb_device *dev,
        if (ret)
                return ret;
 
+       timeout = get_timer(0) + USB_TIMEOUT_MS(pipe);
        if (buffer) {
+               /* DATA stage */
                pid = DWC2_HC_PID_DATA1;
-               ret = chunk_msg(priv, dev, pipe, &pid, usb_pipein(pipe), buffer,
-                               len, false);
+               act_len = 0;
+               do {
+                       if (get_timer(0) > timeout) {
+                               printf("Timeout during CONTROL DATA stage\n");
+                               return -ETIMEDOUT;
+                       }
+                       ret = chunk_msg(priv, dev, pipe, &pid, usb_pipein(pipe),
+                                       buffer, len, false);
+                       act_len += dev->act_len;
+                       buffer += dev->act_len;
+                       len -= dev->act_len;
+               } while (len && (ret == -EAGAIN));
                if (ret)
                        return ret;
-               act_len = dev->act_len;
-       } /* End of DATA stage */
-       else
+               status_direction = usb_pipeout(pipe);
+       } else {
+               /* No-data CONTROL always ends with an IN transaction */
+               status_direction = 1;
                act_len = 0;
+       }
 
        /* STATUS stage */
-       if ((len == 0) || usb_pipeout(pipe))
-               status_direction = 1;
-       else
-               status_direction = 0;
-
        pid = DWC2_HC_PID_DATA1;
-       ret = chunk_msg(priv, dev, pipe, &pid, status_direction,
-                       priv->status_buffer, 0, false);
+       do {
+               ret = chunk_msg(priv, dev, pipe, &pid, status_direction,
+                               priv->status_buffer, 0, false);
+       } while (ret == -EAGAIN);
        if (ret)
                return ret;
 
-- 
2.1.4

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