If the dma channel is not available this driver will still work with interrupts for the analog input subdevice command support.
In addition, only dma channels 1 and 3 are valid for the ISA devices. Signed-off-by: H Hartley Sweeten <[email protected]> Cc: Ian Abbott <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> --- drivers/staging/comedi/drivers/ni_labpc.c | 35 +++++++++++++------------------ 1 file changed, 14 insertions(+), 21 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c index a52647a..744db1f 100644 --- a/drivers/staging/comedi/drivers/ni_labpc.c +++ b/drivers/staging/comedi/drivers/ni_labpc.c @@ -1673,30 +1673,23 @@ int labpc_common_attach(struct comedi_device *dev, unsigned long iobase, } #ifdef CONFIG_ISA_DMA_API - /* grab dma channel */ - if (dma_chan > 3) { - dev_err(dev->class_dev, "invalid dma channel %u\n", dma_chan); - return -EINVAL; - } else if (dma_chan) { - unsigned long dma_flags; - - /* allocate dma buffer */ + if (dma_chan == 1 || dma_chan == 3) { devpriv->dma_buffer = kmalloc(dma_buffer_size, GFP_KERNEL | GFP_DMA); - if (devpriv->dma_buffer == NULL) - return -ENOMEM; - - if (request_dma(dma_chan, dev->board_name)) { - dev_err(dev->class_dev, - "failed to allocate dma channel %u\n", - dma_chan); - return -EINVAL; + if (devpriv->dma_buffer) { + ret = request_dma(dma_chan, dev->board_name); + if (ret == 0) { + unsigned long dma_flags; + + devpriv->dma_chan = dma_chan; + dma_flags = claim_dma_lock(); + disable_dma(devpriv->dma_chan); + set_dma_mode(devpriv->dma_chan, DMA_MODE_READ); + release_dma_lock(dma_flags); + } else { + kfree(devpriv->dma_buffer); + } } - devpriv->dma_chan = dma_chan; - dma_flags = claim_dma_lock(); - disable_dma(devpriv->dma_chan); - set_dma_mode(devpriv->dma_chan, DMA_MODE_READ); - release_dma_lock(dma_flags); } #endif -- 1.8.1.4 _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
