cs5530: add missing ->dma_base check

If ->dma_base is not set (== PCI BAR4 cannot be reserved) then DMA hooks
shouldn't be initialized or bad things will happen.

Also this host driver requires valid PCI BAR4 for normal operation so
check it in ->init_chipset and fail initialization if not set.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/ide/pci/cs5530.c b/drivers/ide/pci/cs5530.c
index acaf71fd4c09..e5949b1d3fb0 100644
--- a/drivers/ide/pci/cs5530.c
+++ b/drivers/ide/pci/cs5530.c
@@ -1,5 +1,5 @@
 /*
- * linux/drivers/ide/pci/cs5530.c               Version 0.73    Mar 10 2007
+ * linux/drivers/ide/pci/cs5530.c               Version 0.74    Jul 28 2007
  *
  * Copyright (C) 2000                   Andre Hedrick <andre@linux-ide.org>
  * Copyright (C) 2000                   Mark Lord <mlord@pobox.com>
@@ -207,6 +207,9 @@ static unsigned int __devinit init_chipset_cs5530 (struct pci_dev *dev, const ch
         struct pci_dev *master_0 = NULL, *cs5530_0 = NULL;
         unsigned long flags;
 
+        if (pci_resource_start(dev, 4) == 0)
+                return -EFAULT;
+
         dev = NULL;
         while ((dev = pci_get_device(PCI_VENDOR_ID_CYRIX, PCI_ANY_ID, dev)) != NULL) {
                 switch (dev->device) {
@@ -325,6 +328,9 @@ static void __devinit init_hwif_cs5530 (ide_hwif_t *hwif)
                         /* needs autotuning later */
         }
 
+        if (hwif->dma_base == 0)
+                return;
+
         hwif->atapi_dma = 1;
         hwif->ultra_mask = 0x07;
         hwif->mwdma_mask = 0x07;