lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

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

Browse Source 
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>
This commit is contained in:
Olivier Sobrie
2014-04-10 21:44:21 +02:00
committed by Marc Kleine-Budde
parent 869ba1e67a
commit e59e36e733
1 changed files with 30 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

55
drivers/net/can/usb/kvaser_usb.c
View File

@@ -379,38 +379,43 @@ static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
void *buf; void *buf;
int actual_len; int actual_len;
int err; int err;
int pos = 0; int pos;
unsigned long to = jiffies + msecs_to_jiffies(USB_RECV_TIMEOUT);
buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL); buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
if (!buf) if (!buf)
return -ENOMEM; return -ENOMEM;
err = usb_bulk_msg(dev->udev, do {
usb_rcvbulkpipe(dev->udev, err = usb_bulk_msg(dev->udev,
dev->bulk_in->bEndpointAddress), usb_rcvbulkpipe(dev->udev,
buf, RX_BUFFER_SIZE, &actual_len, dev->bulk_in->bEndpointAddress),
USB_RECV_TIMEOUT); buf, RX_BUFFER_SIZE, &actual_len,
if (err < 0) USB_RECV_TIMEOUT);
goto end; if (err < 0)
while (pos <= actual_len - MSG_HEADER_LEN) {
tmp = buf + pos;
if (!tmp->len)
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; goto end;
}
pos += tmp->len; pos = 0;
} while (pos <= actual_len - MSG_HEADER_LEN) {
tmp = buf + pos;
if (!tmp->len)
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;
}
pos += tmp->len;
}
} while (time_before(jiffies, to));
err = -EINVAL; err = -EINVAL;