diff mbox

[v6,3/7] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT

Message ID 20150126052406.GD3014@Darwish.PC
State Awaiting Upstream, archived
Delegated to: David Miller
Headers show

Commit Message

Ahmed S. Darwish Jan. 26, 2015, 5:24 a.m. UTC 
From: Ahmed S. Darwish <ahmed.darwish@valeo.com>

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

Patch

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index f0c6207..55407b9 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -1585,7 +1585,7 @@  static int kvaser_usb_probe(struct usb_interface *intf,
 {
 	struct kvaser_usb *dev;
 	int err = -ENOMEM;
-	int i;
+	int i, retry = 3;
 
 	dev = devm_kzalloc(&intf->dev, sizeof(*dev), GFP_KERNEL);
 	if (!dev)
@@ -1603,7 +1603,15 @@  static int kvaser_usb_probe(struct usb_interface *intf,
 
 	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);