[PATCH 3.14 09/33] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT

Greg Kroah-Hartman
2015-02-03T23:18:59Z

From: "Ahmed S. Darwish" <ahmed.darwish@valeo.com>

commit 14c10c2a1dd8eb8e00b750b521753260befa2789 upstream.

On some x86 laptops, plugging a Kvaser device again after an
unplug makes the firmware always ignore the very first command.
For such a case, provide some room for retries instead of
completely exiting the driver init code.

Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/can/usb/kvaser_usb.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -1577,7 +1577,7 @@ static int kvaser_usb_probe(struct usb_i
{
struct kvaser_usb *dev;
int err = -ENOMEM;
- int i;
+ int i, retry = 3;

dev = devm_kzalloc(&intf->dev, sizeof(*dev), GFP_KERNEL);
if (!dev)
@@ -1595,7 +1595,15 @@ static int kvaser_usb_probe(struct usb_i

usb_set_intfdata(intf, dev);

- err = kvaser_usb_get_software_info(dev);
+ /* On some x86 laptops, plugging a Kvaser device again after
+ * an unplug makes the firmware always ignore the very first
+ * command. For such a case, provide some room for retries
+ * instead of completely exiting the driver.
+ */
+ do {
+ err = kvaser_usb_get_software_info(dev);
+ } while (--retry && err == -ETIMEDOUT);
+
if (err) {
dev_err(&intf->dev,
"Cannot get software infos, error %d\n", err);