This patch is ported over by me (Ian Abbott) from the out-of-tree Comedi git repository at "git://comedi.org/git/comedi/comedi.git".
The original patch is by Nicholas Nell. The patch adds support for the COMEDI_POLL ioctl to the ni_pcidio driver. Signed-off-by: Ian Abbott <[email protected]> Cc: Nicholas Nell <[email protected]> Cc: Dan Carpenter <[email protected]> --- Changes for v2: - Don't disable IRQ in ni_pcidio_poll() for nested spinlock as it is already disabled for outer spinlock. - Don't disable IRQ in the hard IRQ handler nidio_interrupt(). --- drivers/staging/comedi/drivers/ni_pcidio.c | 26 +++++++++++++++++++++++--- 1 files changed, 23 insertions(+), 3 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_pcidio.c b/drivers/staging/comedi/drivers/ni_pcidio.c index 5145bf1..88728bd 100644 --- a/drivers/staging/comedi/drivers/ni_pcidio.c +++ b/drivers/staging/comedi/drivers/ni_pcidio.c @@ -483,6 +483,21 @@ void ni_pcidio_event(struct comedi_device *dev, struct comedi_subdevice *s) comedi_event(dev, s); } +static int ni_pcidio_poll(struct comedi_device *dev, struct comedi_subdevice *s) +{ + unsigned long irq_flags; + int count; + + spin_lock_irqsave(&dev->spinlock, irq_flags); + spin_lock(&devpriv->mite_channel_lock); + if (devpriv->di_mite_chan) + mite_sync_input_dma(devpriv->di_mite_chan, s->async); + spin_unlock(&devpriv->mite_channel_lock); + count = s->async->buf_write_count - s->async->buf_read_count; + spin_unlock_irqrestore(&dev->spinlock, irq_flags); + return count; +} + static irqreturn_t nidio_interrupt(int irq, void *d) { struct comedi_device *dev = d; @@ -498,7 +513,6 @@ static irqreturn_t nidio_interrupt(int irq, void *d) int status; int work = 0; unsigned int m_status = 0; - unsigned long irq_flags; /* interrupcions parasites */ if (dev->attached == 0) { @@ -506,6 +520,9 @@ static irqreturn_t nidio_interrupt(int irq, void *d) return IRQ_NONE; } + /* Lock to avoid race with comedi_poll */ + spin_lock(&dev->spinlock); + status = readb(devpriv->mite->daq_io_addr + Interrupt_And_Window_Status); flags = readb(devpriv->mite->daq_io_addr + Group_1_Flags); @@ -519,7 +536,7 @@ static irqreturn_t nidio_interrupt(int irq, void *d) /* printk("buf[4096]=%08x\n", *(unsigned int *)(async->prealloc_buf+4096)); */ - spin_lock_irqsave(&devpriv->mite_channel_lock, irq_flags); + spin_lock(&devpriv->mite_channel_lock); if (devpriv->di_mite_chan) m_status = mite_get_status(devpriv->di_mite_chan); #ifdef MITE_DEBUG @@ -544,7 +561,7 @@ static irqreturn_t nidio_interrupt(int irq, void *d) disable_irq(dev->irq); } } - spin_unlock_irqrestore(&devpriv->mite_channel_lock, irq_flags); + spin_unlock(&devpriv->mite_channel_lock); while (status & DataLeft) { work++; @@ -646,6 +663,8 @@ out: Master_DMA_And_Interrupt_Control); } #endif + + spin_unlock(&dev->spinlock); return IRQ_HANDLED; } @@ -1252,6 +1271,7 @@ static int nidio_attach(struct comedi_device *dev, struct comedi_devconfig *it) s->len_chanlist = 32; /* XXX */ s->buf_change = &ni_pcidio_change; s->async_dma_dir = DMA_BIDIRECTIONAL; + s->poll = &ni_pcidio_poll; writel(0, devpriv->mite->daq_io_addr + Port_IO(0)); writel(0, devpriv->mite->daq_io_addr + Port_Pin_Directions(0)); -- 1.7.8.2 _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
