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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20150203231237.229767305@linuxfoundation.org>
Date:	Tue,  3 Feb 2015 15:14:32 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org,
	"Ahmed S. Darwish" <ahmed.darwish@...eo.com>,
	Marc Kleine-Budde <mkl@...gutronix.de>
Subject: [PATCH 3.14 09/33] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Ahmed S. Darwish" <ahmed.darwish@...eo.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@...eo.com>
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/