pull-request: can 2013-11-25

pull-request: can 2013-11-25

[Marc Kleine-Budde]

Hello David,

here's a pull request for v3.13, i.e. net/master. It consists of a patch by
Oliver Hartkopp which fixes some corner cases in the interrupt handler of the
sja1000 driver. Then there are two patches for the c_can dirver. One by me,
which fixes a runtime pm related "scheduling while atomic" error and patch by
Holger Bechtold that fixes the calculation of the transmitted bytes.

regards,
Marc

---

The following changes since commit 2c7a9dc1641664173211c4ebc5db510a08684c46:

  be2net: Avoid programming permenant MAC by BE3-R VFs (2013-11-23 15:11:07 -0800)

are available in the git repository at:

  git://gitorious.org/linux-can/linux-can.git fixes-for-3.13

for you to fetch changes up to 7ee330c7b3b738847bf297912b371bbcec3bc994:

  can: c_can: fix calculation of transmitted bytes on tx complete (2013-11-25 21:48:54 +0100)

----------------------------------------------------------------
Holger Bechtold (1):
      can: c_can: fix calculation of transmitted bytes on tx complete

Marc Kleine-Budde (1):
      can: c_can: don't call pm_runtime_get_sync() from interrupt context

Oliver Hartkopp (1):
      can: sja1000: fix {pre,post}_irq() handling and IRQ handler return value

 drivers/net/can/c_can/c_can.c     | 22 ++++++++++++++++------
 drivers/net/can/sja1000/sja1000.c | 17 +++++++++--------
 2 files changed, 25 insertions(+), 14 deletions(-)

[PATCH 1/3] can: sja1000: fix {pre,post}_irq() handling and IRQ handler return value

[Marc Kleine-Budde]

From: Oliver Hartkopp <socketcan@hartkopp.net>

This patch fixes the issue that the sja1000_interrupt() function may have
returned IRQ_NONE without processing the optional pre_irq() and post_irq()
function before. Further the irq processing counter 'n' is moved to the end of
the while statement to return correct IRQ_[NONE|HANDLED] values at error
conditions.

Reported-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/sja1000/sja1000.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 7164a99..f17c301 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -494,20 +494,20 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
 	uint8_t isrc, status;
 	int n = 0;
 
-	/* Shared interrupts and IRQ off? */
-	if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
-		return IRQ_NONE;
-
 	if (priv->pre_irq)
 		priv->pre_irq(priv);
 
+	/* Shared interrupts and IRQ off? */
+	if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
+		goto out;
+
 	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
 	       (n < SJA1000_MAX_IRQ)) {
-		n++;
+
 		status = priv->read_reg(priv, SJA1000_SR);
 		/* check for absent controller due to hw unplug */
 		if (status == 0xFF && sja1000_is_absent(priv))
-			return IRQ_NONE;
+			goto out;
 
 		if (isrc & IRQ_WUI)
 			netdev_warn(dev, "wakeup interrupt\n");
@@ -535,7 +535,7 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
 				status = priv->read_reg(priv, SJA1000_SR);
 				/* check for absent controller */
 				if (status == 0xFF && sja1000_is_absent(priv))
-					return IRQ_NONE;
+					goto out;
 			}
 		}
 		if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
@@ -543,8 +543,9 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
 			if (sja1000_err(dev, isrc, status))
 				break;
 		}
+		n++;
 	}
-
+out:
 	if (priv->post_irq)
 		priv->post_irq(priv);
 
-- 
1.8.5.rc0

[PATCH 2/3] can: c_can: don't call pm_runtime_get_sync() from interrupt context

[Marc Kleine-Budde]

The c_can driver contians a callpath (c_can_poll -> c_can_state_change ->
c_can_get_berr_counter) which may call pm_runtime_get_sync() from the IRQ
handler, which is not allowed and results in "BUG: scheduling while atomic".

This problem is fixed by introducing __c_can_get_berr_counter, which will not
call pm_runtime_get_sync().

Reported-by: Andrew Glen <AGlen@bepmarine.com>
Tested-by: Andrew Glen <AGlen@bepmarine.com>
Signed-off-by: Andrew Glen <AGlen@bepmarine.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/c_can/c_can.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index e3fc07c..e59c42b 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -712,22 +712,31 @@ static int c_can_set_mode(struct net_device *dev, enum can_mode mode)
 	return 0;
 }
 
-static int c_can_get_berr_counter(const struct net_device *dev,
-					struct can_berr_counter *bec)
+static int __c_can_get_berr_counter(const struct net_device *dev,
+				    struct can_berr_counter *bec)
 {
 	unsigned int reg_err_counter;
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	c_can_pm_runtime_get_sync(priv);
-
 	reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG);
 	bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >>
 				ERR_CNT_REC_SHIFT;
 	bec->txerr = reg_err_counter & ERR_CNT_TEC_MASK;
 
+	return 0;
+}
+
+static int c_can_get_berr_counter(const struct net_device *dev,
+				  struct can_berr_counter *bec)
+{
+	struct c_can_priv *priv = netdev_priv(dev);
+	int err;
+
+	c_can_pm_runtime_get_sync(priv);
+	err = __c_can_get_berr_counter(dev, bec);
 	c_can_pm_runtime_put_sync(priv);
 
-	return 0;
+	return err;
 }
 
 /*
@@ -872,7 +881,7 @@ static int c_can_handle_state_change(struct net_device *dev,
 	if (unlikely(!skb))
 		return 0;
 
-	c_can_get_berr_counter(dev, &bec);
+	__c_can_get_berr_counter(dev, &bec);
 	reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG);
 	rx_err_passive = (reg_err_counter & ERR_CNT_RP_MASK) >>
 				ERR_CNT_RP_SHIFT;
-- 
1.8.5.rc0

[PATCH 3/3] can: c_can: fix calculation of transmitted bytes on tx complete

[Marc Kleine-Budde]

From: Holger Bechtold <Holger.Bechtold@gmx.net>

The number of bytes transmitted was not updated correctly, if several CAN
messages (with different length) were transmitted in one 'bunch'. Thus
programs like 'ifconfig' showed wrong transmit byte counts. Reason was, that
the message object whose DLC is to be read was not necessarily the active one
at the time when

    priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, 0)) & IF_MCONT_DLC_MASK;

was executed.

Signed-off-by: Holger Bechtold <Holger.Bechtold@gmx.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/c_can/c_can.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index e59c42b..77061ee 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -763,6 +763,7 @@ static void c_can_do_tx(struct net_device *dev)
 		if (!(val & (1 << (msg_obj_no - 1)))) {
 			can_get_echo_skb(dev,
 					msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
+			c_can_object_get(dev, 0, msg_obj_no, IF_COMM_ALL);
 			stats->tx_bytes += priv->read_reg(priv,
 					C_CAN_IFACE(MSGCTRL_REG, 0))
 					& IF_MCONT_DLC_MASK;
-- 
1.8.5.rc0