From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ahmed S. Darwish" Subject: [PATCH v5 4/5] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT Date: Tue, 20 Jan 2015 16:48:34 -0500 Message-ID: <20150120214834.GD16828@linux> References: <20141223154654.GB6460@vivalin-002> <20150120214409.GA16828@linux> <20150120214537.GB16828@linux> <20150120214709.GC16828@linux> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andri Yngvason , Linux-CAN , netdev , LKML To: Olivier Sobrie , Oliver Hartkopp , Wolfgang Grandegger , Marc Kleine-Budde Return-path: Content-Disposition: inline In-Reply-To: <20150120214709.GC16828@linux> Sender: linux-can-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Ahmed S. Darwish 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 --- 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