pull-request: can 2013-11-27

pull-request: can 2013-11-27

[Marc Kleine-Budde]

Hello David,

this is an extention of my pull request from 2013-11-25, it includes an
additional patch.

This series 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.

The fourth patch (the additional one) is by me, it corrects the clock usage in
the flexcan driver.

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-3.13-20131127

for you to fetch changes up to 1a3e5173f5e72cbf7f0c8927b33082e361c16d72:

  can: flexcan: use correct clock as base for bit rate calculation (2013-11-26 15:39:47 +0100)

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

Marc Kleine-Budde (2):
      can: c_can: don't call pm_runtime_get_sync() from interrupt context
      can: flexcan: use correct clock as base for bit rate calculation

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/flexcan.c         |  2 +-
 drivers/net/can/sja1000/sja1000.c | 17 +++++++++--------
 3 files changed, 26 insertions(+), 15 deletions(-)

[PATCH 1/4] 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 2/4] 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 3/4] 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

[PATCH 4/4] can: flexcan: use correct clock as base for bit rate calculation

[Marc Kleine-Budde]

The flexcan IP core uses the peripheral clock ("per") as basic clock for the
bit timing calculation. However the driver uses the the wrong clock ("ipg").
This leads to wrong bit rates if the rates on both clock are different.

This patch fixes the problem by using the correct clock for the bit rate
calculation.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/flexcan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index ae08cf1..aaed97b 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1020,13 +1020,13 @@ static int flexcan_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "no ipg clock defined\n");
 			return PTR_ERR(clk_ipg);
 		}
-		clock_freq = clk_get_rate(clk_ipg);
 
 		clk_per = devm_clk_get(&pdev->dev, "per");
 		if (IS_ERR(clk_per)) {
 			dev_err(&pdev->dev, "no per clock defined\n");
 			return PTR_ERR(clk_per);
 		}
+		clock_freq = clk_get_rate(clk_per);
 	}
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-- 
1.8.5.rc0

Re: pull-request: can 2013-11-27

[David Miller]

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Wed, 27 Nov 2013 22:11:31 +0100

> this is an extention of my pull request from 2013-11-25, it includes an
> additional patch.
> 
> This series 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.
> 
> The fourth patch (the additional one) is by me, it corrects the clock usage in
> the flexcan driver.

Pulled, thanks Marc.