diff options
| author | H Hartley Sweeten <hsweeten@visionengravers.com> | 2015-01-13 10:16:25 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-17 14:31:29 -0800 |
| commit | 7877445b5c1bb10078ef72db65df1553f4cbd73e (patch) | |
| tree | 45f74a0cd2906413e7cb1aa10ee3d4f59af81260 | |
| parent | f609c29dfb7a5729bfab9384fad45fbf12653c67 (diff) | |
staging: comedi: dt282x: introduce dt282x_isadma_disable()
According to Documentation/DMA-ISA-LPC.txt, the DMA lock needs to be
claimed before using any of the ISA DMA routines. Introduce a helper
function to disable the ISA DMA controller and add the necessary
locking calls.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/comedi/drivers/dt282x.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c index 2d01c6cfbb4d..54c679a0387b 100644 --- a/drivers/staging/comedi/drivers/dt282x.c +++ b/drivers/staging/comedi/drivers/dt282x.c @@ -339,6 +339,15 @@ static void dt282x_isadma_program(struct dt282x_dma_desc *dma) release_dma_lock(flags); } +static void dt282x_isadma_disable(struct dt282x_dma_desc *dma) +{ + unsigned long flags; + + flags = claim_dma_lock(); + disable_dma(dma->chan); + release_dma_lock(flags); +} + static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n) { struct dt282x_private *devpriv = dev->private; @@ -377,9 +386,10 @@ static int dt282x_prep_ao_dma(struct comedi_device *dev, int dma_index, int n) static void dt282x_disable_dma(struct comedi_device *dev) { struct dt282x_private *devpriv = dev->private; + int i; - disable_dma(devpriv->dma_desc[0].chan); - disable_dma(devpriv->dma_desc[1].chan); + for (i = 0; i < 2; i++) + dt282x_isadma_disable(&devpriv->dma_desc[i]); } static unsigned int dt282x_ns_to_timer(unsigned int *ns, unsigned int flags) @@ -463,7 +473,7 @@ static void dt282x_ao_dma_interrupt(struct comedi_device *dev, outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE, dev->iobase + DT2821_SUPCSR_REG); - disable_dma(dma->chan); + dt282x_isadma_disable(dma); if (!dt282x_ao_setup_dma(dev, s, devpriv->cur_dma)) s->async->events |= COMEDI_CB_OVERFLOW; @@ -482,7 +492,7 @@ static void dt282x_ai_dma_interrupt(struct comedi_device *dev, outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE, dev->iobase + DT2821_SUPCSR_REG); - disable_dma(dma->chan); + dt282x_isadma_disable(dma); dt282x_munge(dev, s, dma->virt_addr, dma->size); ret = comedi_buf_write_samples(s, dma->virt_addr, nsamples); |