4.4-stable review patch. If anyone has any objections, please let me know.
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From: Anssi Hannula anssi.hannula@bitwise.fi
commit 2f4f0f338cf453bfcdbcf089e177c16f35f023c8 upstream.
xcan_interrupt() clears ERROR|RXOFLV|BSOFF|ARBLST interrupts if any of them is asserted. This does not take into account that some of them could have been asserted between interrupt status read and interrupt clear, therefore clearing them without handling them.
Fix the code to only clear those interrupts that it knows are asserted and therefore going to be processed in xcan_err_interrupt().
Fixes: b1201e44f50b ("can: xilinx CAN controller support") Signed-off-by: Anssi Hannula anssi.hannula@bitwise.fi Cc: Michal Simek michal.simek@xilinx.com Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/can/xilinx_can.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
--- a/drivers/net/can/xilinx_can.c +++ b/drivers/net/can/xilinx_can.c @@ -937,6 +937,7 @@ static irqreturn_t xcan_interrupt(int ir struct net_device *ndev = (struct net_device *)dev_id; struct xcan_priv *priv = netdev_priv(ndev); u32 isr, ier; + u32 isr_errors;
/* Get the interrupt status from Xilinx CAN */ isr = priv->read_reg(priv, XCAN_ISR_OFFSET); @@ -955,11 +956,10 @@ static irqreturn_t xcan_interrupt(int ir xcan_tx_interrupt(ndev, isr);
/* Check for the type of error interrupt and Processing it */ - if (isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | - XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK)) { - priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_ERROR_MASK | - XCAN_IXR_RXOFLW_MASK | XCAN_IXR_BSOFF_MASK | - XCAN_IXR_ARBLST_MASK)); + isr_errors = isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK | + XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK); + if (isr_errors) { + priv->write_reg(priv, XCAN_ICR_OFFSET, isr_errors); xcan_err_interrupt(ndev, isr); }