From 5793affe8c723ece8114b898ab9003c7d97f86d1 Mon Sep 17 00:00:00 2001 From: Jeppe Ledet-Pedersen Date: Wed, 29 Apr 2015 17:05:01 +0200 Subject: [PATCH] net: can: xilinx_can: fix extended frame handling 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 Acked-by: Kedareswara rao Appana Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- 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]); -- 2.20.1