diff options
Diffstat (limited to 'drivers/net/can/spi/mcp251x.c')
| -rw-r--r-- | drivers/net/can/spi/mcp251x.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index ec5c64006a16..74906aa98be3 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -1201,6 +1201,7 @@ static int mcp251x_open(struct net_device *net) { struct mcp251x_priv *priv = netdev_priv(net); struct spi_device *spi = priv->spi; + bool release_irq = false; unsigned long flags = 0; int ret; @@ -1244,12 +1245,24 @@ static int mcp251x_open(struct net_device *net) return 0; out_free_irq: - free_irq(spi->irq, priv); + /* The IRQ handler might be running, and if so it will be waiting + * for the lock. But free_irq() must wait for the handler to finish + * so calling it here would deadlock. + * + * Setting priv->force_quit will let the handler exit right away + * without any access to the hardware. This make it safe to call + * free_irq() after the lock is released. + */ + priv->force_quit = 1; + release_irq = true; + mcp251x_hw_sleep(spi); out_close: mcp251x_power_enable(priv->transceiver, 0); close_candev(net); mutex_unlock(&priv->mcp_lock); + if (release_irq) + free_irq(spi->irq, priv); return ret; } |