diff options
Diffstat (limited to 'drivers/net/can/spi/mcp251x.c')
| -rw-r--r-- | drivers/net/can/spi/mcp251x.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index bb20a9b75cc6..32bd593a39f1 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -756,9 +756,6 @@ 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); @@ -768,6 +765,18 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) if (mcp251x_is_2510(spi)) mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00); + + /* check if buffer 1 is already known to be full, no need to re-read */ + if (!(intf & CANINTF_RX1IF)) { + u8 intf1, eflag1; + + /* intf needs to be read again to avoid a race condition */ + mcp251x_read_2regs(spi, CANINTF, &intf1, &eflag1); + + /* combine flags from both operations for error handling */ + intf |= intf1; + eflag |= eflag1; + } } /* receive buffer 1 */ @@ -778,6 +787,9 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) clear_intf |= CANINTF_RX1IF; } + /* mask out flags we don't care about */ + intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR; + /* any error or tx interrupt we need to clear? */ if (intf & (CANINTF_ERR | CANINTF_TX)) clear_intf |= intf & (CANINTF_ERR | CANINTF_TX); |