From 5601b2dfae86198667dd6e075a074fbef0c83423 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 20 Oct 2010 00:02:25 +0000 Subject: [PATCH] can: mcp251x: fix endless loop in interrupt handler if CANINTF_MERRF is set Commit d3cd15657516141adce387810be8cb377baf020e introduced a bug, the interrupt handler would loop endlessly if the CANINTF_MERRF bit is set, because it's not cleared. This patch fixes the problem by masking out the CANINTF_MERRF and all other non interesting bits. Signed-off-by: Marc Kleine-Budde Signed-off-by: David S. Miller --- drivers/net/can/mcp251x.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c index c664be261e98..59f40bce1ffc 100644 --- a/drivers/net/can/mcp251x.c +++ b/drivers/net/can/mcp251x.c @@ -125,8 +125,9 @@ # define CANINTF_TX0IF 0x04 # define CANINTF_RX1IF 0x02 # define CANINTF_RX0IF 0x01 -# define CANINTF_ERR_TX \ - (CANINTF_ERRIF | CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF) +# define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF) +# define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF) +# define CANINTF_ERR (CANINTF_ERRIF) #define EFLG 0x2d # define EFLG_EWARN 0x01 # define EFLG_RXWAR 0x02 @@ -790,6 +791,9 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) mcp251x_read_2regs(spi, CANINTF, &intf, &eflag); + /* mask out flags we don't care about */ + intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR; + /* receive buffer 0 */ if (intf & CANINTF_RX0IF) { mcp251x_hw_rx(spi, 0); @@ -810,8 +814,8 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) } /* any error or tx interrupt we need to clear? */ - if (intf & CANINTF_ERR_TX) - clear_intf |= intf & CANINTF_ERR_TX; + if (intf & (CANINTF_ERR | CANINTF_TX)) + clear_intf |= intf & (CANINTF_ERR | CANINTF_TX); if (clear_intf) mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00); @@ -887,7 +891,7 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) if (intf == 0) break; - if (intf & (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)) { + if (intf & CANINTF_TX) { net->stats.tx_packets++; net->stats.tx_bytes += priv->tx_len - 1; if (priv->tx_len) { -- 2.34.1