pdc202xx_new: 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>

drivers/ide/pci/pdc202xx_new.c

@@ -378,6 +378,9 @@ static unsigned int __devinit init_chipset_pdcnew(struct pci_dev *dev, const cha
 	int f, r;
 	u8 pll_ctl0, pll_ctl1;
 
+	if (dma_base == 0)
+		return -EFAULT;
+
 #ifdef CONFIG_PPC_PMAC
 	apple_kiwi_init(dev);
 #endif
@@ -494,15 +497,18 @@ static void __devinit init_hwif_pdc202new(ide_hwif_t *hwif)
 	hwif->speedproc = &pdcnew_tune_chipset;
 	hwif->resetproc = &pdcnew_reset;
 
+	hwif->err_stops_fifo = 1;
+
 	hwif->drives[0].autotune = hwif->drives[1].autotune = 1;
 
+	if (hwif->dma_base == 0)
+		return;
+
 	hwif->atapi_dma  = 1;
 
 	hwif->ultra_mask = hwif->cds->udma_mask;
 	hwif->mwdma_mask = 0x07;
 
-	hwif->err_stops_fifo = 1;
-
 	hwif->ide_dma_check = &pdcnew_config_drive_xfer_rate;
 
 	if (hwif->cbl != ATA_CBL_PATA40_SHORT)