I/OAT: clean up of dca provider start and stop

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>

1 files changed, 5 insertions, 6 deletions

diff --git a/drivers/dma/ioat.c b/drivers/dma/ioat.c
index 54fdeb7c4945..a45872f32d50 100644
--- a/drivers/dma/ioat.c
+++ b/drivers/dma/ioat.c
@@ -71,7 +71,7 @@ static int ioat_setup_functionality(struct pci_dev *pdev, void __iomem *iobase)
         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:
@@ -85,17 +85,16 @@ static void ioat_shutdown_functionality(struct pci_dev *pdev)
 {
         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 = {