--- a/drivers/ide/pci/pdc202xx_old.c
+++ b/drivers/ide/pci/pdc202xx_old.c
@@ -253,23 +253,23 @@ static int pdc202xx_tune_chipset (ide_dr
 	pci_read_config_byte(dev, (drive_pci)|0x03, &DP);
 
 	if (speed < XFER_SW_DMA_0) {
-		if ((AP & 0x0F) || (BP & 0x07)) {
+		if ((AP & 0x0F) || (BP & 0x17)) {
 			/* clear PIO modes of lower 8421 bits of A Register */
 			pci_write_config_byte(dev, (drive_pci), AP &~0x0F);
 			pci_read_config_byte(dev, (drive_pci), &AP);
 
 			/* clear PIO modes of lower 421 bits of B Register */
-			pci_write_config_byte(dev, (drive_pci)|0x01, BP &~0x07);
+			pci_write_config_byte(dev, (drive_pci)|0x01, BP &~0x17);
 			pci_read_config_byte(dev, (drive_pci)|0x01, &BP);
 
 			pci_read_config_byte(dev, (drive_pci), &AP);
 			pci_read_config_byte(dev, (drive_pci)|0x01, &BP);
 		}
 	} else {
-		if ((BP & 0xF0) && (CP & 0x0F)) {
+		if ((BP & 0xE0) && (CP & 0x0F)) {
 			/* clear DMA modes of upper 842 bits of B Register */
 			/* clear PIO forced mode upper 1 bit of B Register */
-			pci_write_config_byte(dev, (drive_pci)|0x01, BP &~0xF0);
+			pci_write_config_byte(dev, (drive_pci)|0x01, BP &~0xE0);
 			pci_read_config_byte(dev, (drive_pci)|0x01, &BP);
 
 			/* clear DMA modes of lower 8421 bits of C Register */
@@ -373,6 +373,9 @@ static int config_chipset_for_dma (ide_d
 	u8 ultra_66		= ((id->dma_ultra & 0x0010) ||
 				   (id->dma_ultra & 0x0008)) ? 1 : 0;
 
+	if (hwif->rqsize != 256)
+		hwif->rqsize = 256;
+
 	switch(dev->device) {
 		case PCI_DEVICE_ID_PROMISE_20267:
 		case PCI_DEVICE_ID_PROMISE_20265: