[PATCH] net: can: xilinx_can: fix extended frame handling

[PATCH] net: can: xilinx_can: fix extended frame handling

[Jeppe Ledet-Pedersen]

Using IDR_SRR in RXFIFO_ID to test for the presence of data is only
valid for standard frames. For extended frames the bit is always 1 and
IDR_RTR should be used instead. This patch switches the check to use
CAN_RTR_FLAG which is correctly set when reading the ID.

The patch also changes the DW1/DW2 to be read unconditionally, since
this is necessary to remove the frame from the RXFIFO.

Signed-off-by: Jeppe Ledet-Pedersen <jlp@gomspace.com>
Acked-by: Kedareswara rao Appana <appanad@xilinx.com>
---
 drivers/net/can/xilinx_can.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 6c67643..0b27769 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -509,10 +509,11 @@ static int xcan_rx(struct net_device *ndev)
 			cf->can_id |= CAN_RTR_FLAG;
 	}
 
-	if (!(id_xcan & XCAN_IDR_SRR_MASK)) {
-		data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET);
-		data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET);
+	/* DW1/DW2 must always be read to remove message from RXFIFO */
+	data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET);
+	data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET);
 
+	if (!(cf->can_id & CAN_RTR_FLAG)) {
 		/* Change Xilinx CAN data format to socketCAN data format */
 		if (cf->can_dlc > 0)
 			*(__be32 *)(cf->data) = cpu_to_be32(data[0]);
-- 
2.1.0

Re: [PATCH] net: can: xilinx_can: fix extended frame handling

[Marc Kleine-Budde]

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On 04/29/2015 05:05 PM, Jeppe Ledet-Pedersen wrote:
> Using IDR_SRR in RXFIFO_ID to test for the presence of data is only
> valid for standard frames. For extended frames the bit is always 1 and
> IDR_RTR should be used instead. This patch switches the check to use
> CAN_RTR_FLAG which is correctly set when reading the ID.
> 
> The patch also changes the DW1/DW2 to be read unconditionally, since
> this is necessary to remove the frame from the RXFIFO.
> 
> Signed-off-by: Jeppe Ledet-Pedersen <jlp@gomspace.com>
> Acked-by: Kedareswara rao Appana <appanad@xilinx.com>

Applied to can. Added stable on Cc.

Thanks,
Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
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pull-request: can 2015-05-01

[Marc Kleine-Budde]

Hello David,

this is a pull request of a single patch for net/master.

The patch is contributed by Jeppe Ledet-Pedersen, it fixes the extended frame
handling in the xilinx driver.

regards,
Marc

---

The following changes since commit e813bb2b955d9f72c94be7d592746b49929a499b:

  net: fec: Fix RGMII-ID mode (2015-04-30 16:48:53 -0400)

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-4.1-20150501

for you to fetch changes up to 5793affe8c723ece8114b898ab9003c7d97f86d1:

  net: can: xilinx_can: fix extended frame handling (2015-05-01 10:11:46 +0200)

----------------------------------------------------------------
linux-can-fixes-for-4.1-20150501

----------------------------------------------------------------
Jeppe Ledet-Pedersen (1):
      net: can: xilinx_can: fix extended frame handling

 drivers/net/can/xilinx_can.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

[PATCH] net: can: xilinx_can: fix extended frame handling

[Marc Kleine-Budde]

From: Jeppe Ledet-Pedersen <jlp@gomspace.com>

Using IDR_SRR in RXFIFO_ID to test for the presence of data is only
valid for standard frames. For extended frames the bit is always 1 and
IDR_RTR should be used instead. This patch switches the check to use
CAN_RTR_FLAG which is correctly set when reading the ID.

The patch also changes the DW1/DW2 to be read unconditionally, since
this is necessary to remove the frame from the RXFIFO.

Signed-off-by: Jeppe Ledet-Pedersen <jlp@gomspace.com>
Acked-by: Kedareswara rao Appana <appanad@xilinx.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/xilinx_can.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 6bddfe062b51..fc55e8e0351d 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -509,10 +509,11 @@ static int xcan_rx(struct net_device *ndev)
 			cf->can_id |= CAN_RTR_FLAG;
 	}
 
-	if (!(id_xcan & XCAN_IDR_SRR_MASK)) {
-		data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET);
-		data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET);
+	/* DW1/DW2 must always be read to remove message from RXFIFO */
+	data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET);
+	data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET);
 
+	if (!(cf->can_id & CAN_RTR_FLAG)) {
 		/* Change Xilinx CAN data format to socketCAN data format */
 		if (cf->can_dlc > 0)
 			*(__be32 *)(cf->data) = cpu_to_be32(data[0]);
-- 
2.1.4

Re: pull-request: can 2015-05-01

[David Miller]

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Fri,  1 May 2015 10:28:57 +0200

> this is a pull request of a single patch for net/master.
> 
> The patch is contributed by Jeppe Ledet-Pedersen, it fixes the extended frame
> handling in the xilinx driver.

Pulled, thanks Marc.