diff options
Diffstat (limited to 'drivers/uio/uio_dmem_genirq.c')
| -rw-r--r-- | drivers/uio/uio_dmem_genirq.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/uio/uio_dmem_genirq.c b/drivers/uio/uio_dmem_genirq.c index 1106f3376404..5313307c2754 100644 --- a/drivers/uio/uio_dmem_genirq.c +++ b/drivers/uio/uio_dmem_genirq.c @@ -41,6 +41,11 @@ struct uio_dmem_genirq_platdata { unsigned int refcnt; }; +/* Bits in uio_dmem_genirq_platdata.flags */ +enum { + UIO_IRQ_DISABLED = 0, +}; + static int uio_dmem_genirq_open(struct uio_info *info, struct inode *inode) { struct uio_dmem_genirq_platdata *priv = info->priv; @@ -110,8 +115,10 @@ static irqreturn_t uio_dmem_genirq_handler(int irq, struct uio_info *dev_info) * remember the state so we can allow user space to enable it later. */ - if (!test_and_set_bit(0, &priv->flags)) + spin_lock(&priv->lock); + if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags)) disable_irq_nosync(irq); + spin_unlock(&priv->lock); return IRQ_HANDLED; } @@ -125,20 +132,19 @@ static int uio_dmem_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on) * in the interrupt controller, but keep track of the * state to prevent per-irq depth damage. * - * Serialize this operation to support multiple tasks. + * Serialize this operation to support multiple tasks and concurrency + * with irq handler on SMP systems. */ spin_lock_irqsave(&priv->lock, flags); if (irq_on) { - if (test_and_clear_bit(0, &priv->flags)) + if (__test_and_clear_bit(UIO_IRQ_DISABLED, &priv->flags)) enable_irq(dev_info->irq); - spin_unlock_irqrestore(&priv->lock, flags); } else { - if (!test_and_set_bit(0, &priv->flags)) { - spin_unlock_irqrestore(&priv->lock, flags); - disable_irq(dev_info->irq); - } + if (!__test_and_set_bit(UIO_IRQ_DISABLED, &priv->flags)) + disable_irq_nosync(dev_info->irq); } + spin_unlock_irqrestore(&priv->lock, flags); return 0; } |