Don't start ioat_dca if ioat_dma didn't start, and then stop ioat_dca
before stopping ioat_dma.  Since the ioat_dma side does the pci device
work, This takes care of ioat_dca trying to use a bad device reference.
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
        switch (version) {
        case IOAT_VER_1_2:
                device->dma = ioat_dma_probe(pdev, iobase);
-               if (ioat_dca_enabled)
+               if (device->dma && ioat_dca_enabled)
                        device->dca = ioat_dca_init(pdev, iobase);
                break;
        default:
 {
        struct ioat_device *device = pci_get_drvdata(pdev);
 
-       if (device->dma) {
-               ioat_dma_remove(device->dma);
-               device->dma = NULL;
-       }
-
        if (device->dca) {
                unregister_dca_provider(device->dca);
                free_dca_provider(device->dca);
                device->dca = NULL;
        }
 
+       if (device->dma) {
+               ioat_dma_remove(device->dma);
+               device->dma = NULL;
+       }
 }
 
 static struct pci_driver ioat_pci_driver = {
 
        struct dma_chan *chan, *_chan;
        struct ioat_dma_chan *ioat_chan;
 
-       dma_async_device_unregister(&device->common);
-
        ioat_dma_remove_interrupts(device);
 
+       dma_async_device_unregister(&device->common);
+
        pci_pool_destroy(device->dma_pool);
        pci_pool_destroy(device->completion_pool);