can: kvaser_usb: add retries/timeout to kvaser_usb_wait_msg()

On some Kvaser hardware, the firmware returns extra messages after the
request for card info. For instance on a Leaf Light v2:
  --> CMD_GET_CARD_INFO
  <-- CMD_USB_THROTTLE
  <-- CMD_GET_CARD_INFO2
  <-- CMD_GET_CARD_INFO_REQ
When it happens, the probing function fails because we only read
the first usb message.

To overcome this issue, we add a mechanism of retries to the
kvaser_usb_wait_msg() function.

I tested this patch with the following hardware:
 - Kvaser Leaf Light
 - Kvaser Leaf Light v2
 - Kvaser USBCan R

This patch is necessary for the Leaf Light v2 hardware.

Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 27 insertions, 22 deletions

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index 4ca46edc061d..7a1c5ec23268 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -379,38 +379,43 @@ static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
         void *buf;
         int actual_len;
         int err;
-        int pos = 0;
+        int pos;
+        unsigned long to = jiffies + msecs_to_jiffies(USB_RECV_TIMEOUT);
 
         buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
         if (!buf)
                 return -ENOMEM;
 
-        err = usb_bulk_msg(dev->udev,
-                           usb_rcvbulkpipe(dev->udev,
-                                           dev->bulk_in->bEndpointAddress),
-                           buf, RX_BUFFER_SIZE, &actual_len,
-                           USB_RECV_TIMEOUT);
-        if (err < 0)
-                goto end;
+        do {
+                err = usb_bulk_msg(dev->udev,
+                                   usb_rcvbulkpipe(dev->udev,
+                                        dev->bulk_in->bEndpointAddress),
+                                   buf, RX_BUFFER_SIZE, &actual_len,
+                                   USB_RECV_TIMEOUT);
+                if (err < 0)
+                        goto end;
 
-        while (pos <= actual_len - MSG_HEADER_LEN) {
-                tmp = buf + pos;
+                pos = 0;
+                while (pos <= actual_len - MSG_HEADER_LEN) {
+                        tmp = buf + pos;
 
-                if (!tmp->len)
-                        break;
+                        if (!tmp->len)
+                                break;
 
-                if (pos + tmp->len > actual_len) {
-                        dev_err(dev->udev->dev.parent, "Format error\n");
-                        break;
-                }
+                        if (pos + tmp->len > actual_len) {
+                                dev_err(dev->udev->dev.parent,
+                                        "Format error\n");
+                                break;
+                        }
 
-                if (tmp->id == id) {
-                        memcpy(msg, tmp, tmp->len);
-                        goto end;
-                }
+                        if (tmp->id == id) {
+                                memcpy(msg, tmp, tmp->len);
+                                goto end;
+                        }
 
-                pos += tmp->len;
-        }
+                        pos += tmp->len;
+                }
+        } while (time_before(jiffies, to));
 
         err = -EINVAL;