[PATCH v5 4/5] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT
From: Ahmed S. Darwish <hidden>
Date: 2015-01-20 21:48:41
Also in:
linux-can, lkml
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
From: Ahmed S. Darwish <redacted> 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 completly exiting the driver init code. Signed-off-by: Ahmed S. Darwish <redacted> --- drivers/net/can/usb/kvaser_usb.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index 640b0eb..068e76c 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c@@ -1614,7 +1614,7 @@ 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)
@@ -1632,7 +1632,15 @@ 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 completly 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);
--
1.9.1