pull-request: can 2015-01-27

pull-request: can 2015-01-27

[Marc Kleine-Budde]

Hello David,

this is another pull request for net/master which consists of 4 patches.

All 4 patches are contributed by Ahmed S. Darwish, he fixes more problems in
the kvaser_usb driver.

David, please merge net/master to net-next/master, as we have more kvaser_usb
patches in the queue, that target net-next.

regards,
Marc

The following changes since commit 600ddd6825543962fb807884169e57b580dba208:

  net: sctp: fix slab corruption from use after free on INIT collisions (2015-01-26 17:02:05 -0800)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git tags/linux-can-fixes-for-3.19-20150127

for you to fetch changes up to e638642b08c170d2021b706f0b1c4f4ae93d8cbd:

  can: kvaser_usb: Fix state handling upon BUS_ERROR events (2015-01-27 08:55:09 +0100)

----------------------------------------------------------------
linux-can-fixes-for-3.19-20150127

----------------------------------------------------------------
Ahmed S. Darwish (4):
      can: kvaser_usb: Do not sleep in atomic context
      can: kvaser_usb: Send correct context to URB completion
      can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT
      can: kvaser_usb: Fix state handling upon BUS_ERROR events

 drivers/net/can/usb/kvaser_usb.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

[PATCH 1/4] can: kvaser_usb: Do not sleep in atomic context

[Marc Kleine-Budde]

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

Upon receiving a hardware event with the BUS_RESET flag set,
the driver kills all of its anchored URBs and resets all of
its transmit URB contexts.

Unfortunately it does so under the context of URB completion
handler `kvaser_usb_read_bulk_callback()', which is often
called in an atomic context.

While the device is flooded with many received error packets,
usb_kill_urb() typically sleeps/reschedules till the transfer
request of each killed URB in question completes, leading to
the sleep in atomic bug. [3]

In v2 submission of the original driver patch [1], it was
stated that the URBs kill and tx contexts reset was needed
since we don't receive any tx acknowledgments later and thus
such resources will be locked down forever. Fortunately this
is no longer needed since an earlier bugfix in this patch
series is now applied: all tx URB contexts are reset upon CAN
channel close. [2]

Moreover, a BUS_RESET is now treated _exactly_ like a BUS_OFF
event, which is the recommended handling method advised by
the device manufacturer.

[1] http://article.gmane.org/gmane.linux.network/239442
    http://www.webcitation.org/6Vr2yagAQ

[2] can: kvaser_usb: Reset all URB tx contexts upon channel close
    889b77f7fd2bcc922493d73a4c51d8a851505815

[3] Stacktrace:

 <IRQ>  [<ffffffff8158de87>] dump_stack+0x45/0x57
 [<ffffffff8158b60c>] __schedule_bug+0x41/0x4f
 [<ffffffff815904b1>] __schedule+0x5f1/0x700
 [<ffffffff8159360a>] ? _raw_spin_unlock_irqrestore+0xa/0x10
 [<ffffffff81590684>] schedule+0x24/0x70
 [<ffffffff8147d0a5>] usb_kill_urb+0x65/0xa0
 [<ffffffff81077970>] ? prepare_to_wait_event+0x110/0x110
 [<ffffffff8147d7d8>] usb_kill_anchored_urbs+0x48/0x80
 [<ffffffffa01f4028>] kvaser_usb_unlink_tx_urbs+0x18/0x50 [kvaser_usb]
 [<ffffffffa01f45d0>] kvaser_usb_rx_error+0xc0/0x400 [kvaser_usb]
 [<ffffffff8108b14a>] ? vprintk_default+0x1a/0x20
 [<ffffffffa01f5241>] kvaser_usb_read_bulk_callback+0x4c1/0x5f0 [kvaser_usb]
 [<ffffffff8147a73e>] __usb_hcd_giveback_urb+0x5e/0xc0
 [<ffffffff8147a8a1>] usb_hcd_giveback_urb+0x41/0x110
 [<ffffffffa0008748>] finish_urb+0x98/0x180 [ohci_hcd]
 [<ffffffff810cd1a7>] ? acct_account_cputime+0x17/0x20
 [<ffffffff81069f65>] ? local_clock+0x15/0x30
 [<ffffffffa000a36b>] ohci_work+0x1fb/0x5a0 [ohci_hcd]
 [<ffffffff814fbb31>] ? process_backlog+0xb1/0x130
 [<ffffffffa000cd5b>] ohci_irq+0xeb/0x270 [ohci_hcd]
 [<ffffffff81479fc1>] usb_hcd_irq+0x21/0x30
 [<ffffffff8108bfd3>] handle_irq_event_percpu+0x43/0x120
 [<ffffffff8108c0ed>] handle_irq_event+0x3d/0x60
 [<ffffffff8108ec84>] handle_fasteoi_irq+0x74/0x110
 [<ffffffff81004dfd>] handle_irq+0x1d/0x30
 [<ffffffff81004727>] do_IRQ+0x57/0x100
 [<ffffffff8159482a>] common_interrupt+0x6a/0x6a

Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/usb/kvaser_usb.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index c32cd61073bc..978a25e9cd3c 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -662,11 +662,6 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
 	priv = dev->nets[channel];
 	stats = &priv->netdev->stats;
 
-	if (status & M16C_STATE_BUS_RESET) {
-		kvaser_usb_unlink_tx_urbs(priv);
-		return;
-	}
-
 	skb = alloc_can_err_skb(priv->netdev, &cf);
 	if (!skb) {
 		stats->rx_dropped++;
@@ -677,7 +672,7 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
 
 	netdev_dbg(priv->netdev, "Error status: 0x%02x\n", status);
 
-	if (status & M16C_STATE_BUS_OFF) {
+	if (status & (M16C_STATE_BUS_OFF | M16C_STATE_BUS_RESET)) {
 		cf->can_id |= CAN_ERR_BUSOFF;
 
 		priv->can.can_stats.bus_off++;
-- 
2.1.4

[PATCH 2/4] can: kvaser_usb: Send correct context to URB completion

[Marc Kleine-Budde]

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

Send expected argument to the URB completion hander: a CAN
netdevice instead of the network interface private context
`kvaser_usb_net_priv'.

This was discovered by having some garbage in the kernel
log in place of the netdevice names: can0 and can1.

Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/usb/kvaser_usb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index 978a25e9cd3c..f0c62075df0a 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -587,7 +587,7 @@ static int kvaser_usb_simple_msg_async(struct kvaser_usb_net_priv *priv,
 			  usb_sndbulkpipe(dev->udev,
 					  dev->bulk_out->bEndpointAddress),
 			  buf, msg->len,
-			  kvaser_usb_simple_msg_callback, priv);
+			  kvaser_usb_simple_msg_callback, netdev);
 	usb_anchor_urb(urb, &priv->tx_submitted);
 
 	err = usb_submit_urb(urb, GFP_ATOMIC);
-- 
2.1.4

[PATCH 3/4] can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT

[Marc Kleine-Budde]

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>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 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 f0c62075df0a..55407b9663a6 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);
-- 
2.1.4

[PATCH 4/4] can: kvaser_usb: Fix state handling upon BUS_ERROR events

[Marc Kleine-Budde]

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

While being in an ERROR_WARNING state, and receiving further
bus error events with error counters still in the ERROR_WARNING
range of 97-127 inclusive, the state handling code erroneously
reverts back to ERROR_ACTIVE.

Per the CAN standard, only revert to ERROR_ACTIVE when the
error counters are less than 96.

Moreover, in certain Kvaser models, the BUS_ERROR flag is
always set along with undefined bits in the M16C status
register. Thus use bitwise operators instead of full equality
for checking that register against bus errors.

Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/usb/kvaser_usb.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index 55407b9663a6..7af379ca861b 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -698,9 +698,7 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
 		}
 
 		new_state = CAN_STATE_ERROR_PASSIVE;
-	}
-
-	if (status == M16C_STATE_BUS_ERROR) {
+	} else if (status & M16C_STATE_BUS_ERROR) {
 		if ((priv->can.state < CAN_STATE_ERROR_WARNING) &&
 		    ((txerr >= 96) || (rxerr >= 96))) {
 			cf->can_id |= CAN_ERR_CRTL;
@@ -710,7 +708,8 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
 
 			priv->can.can_stats.error_warning++;
 			new_state = CAN_STATE_ERROR_WARNING;
-		} else if (priv->can.state > CAN_STATE_ERROR_ACTIVE) {
+		} else if ((priv->can.state > CAN_STATE_ERROR_ACTIVE) &&
+			   ((txerr < 96) && (rxerr < 96))) {
 			cf->can_id |= CAN_ERR_PROT;
 			cf->data[2] = CAN_ERR_PROT_ACTIVE;
 
-- 
2.1.4

Re: pull-request: can 2015-01-27

[David Miller]

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Tue, 27 Jan 2015 09:01:23 +0100

> this is another pull request for net/master which consists of 4 patches.
> 
> All 4 patches are contributed by Ahmed S. Darwish, he fixes more problems in
> the kvaser_usb driver.

Pulled, thanks.

> David, please merge net/master to net-next/master, as we have more kvaser_usb
> patches in the queue, that target net-next.

I will do so after I send a pull request for 'net' to Linus and he takes it
in, thanks.

Re: pull-request: can 2015-01-27

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 909 bytes --]

On 01/27/2015 09:13 AM, David Miller wrote:
> From: Marc Kleine-Budde <mkl@pengutronix.de>
> Date: Tue, 27 Jan 2015 09:01:23 +0100
> 
>> this is another pull request for net/master which consists of 4 patches.
>>
>> All 4 patches are contributed by Ahmed S. Darwish, he fixes more problems in
>> the kvaser_usb driver.
> 
> Pulled, thanks.

That was fast :)

>> David, please merge net/master to net-next/master, as we have more kvaser_usb
>> patches in the queue, that target net-next.
> 
> I will do so after I send a pull request for 'net' to Linus and he takes it
> in, thanks.

Thanks, I'll notice.

Marc

-- 
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