diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 915a55a..0eea6bd 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -90,6 +90,9 @@ static int ata_probe_timeout = ATA_TMOUT_INTERNAL / HZ;
 module_param(ata_probe_timeout, int, 0444);
 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
 
+int ata_debug_cocktail = 0;
+module_param_named(debug_cocktail, ata_debug_cocktail, int, 0444);
+
 MODULE_AUTHOR("Jeff Garzik");
 MODULE_DESCRIPTION("Library module for ATA devices");
 MODULE_LICENSE("GPL");
@@ -2227,6 +2230,10 @@ int ata_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev)
 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
 		dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
+		if (dev->pio_mode && ata_debug_cocktail & (1 << 1)) {
+			ata_port_printk(ap, KERN_INFO, "XXX force PIO0\n");
+			dev->pio_mode = XFER_PIO_0;
+		}
 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
 
 		found = 1;
@@ -3124,6 +3131,29 @@ static void ata_dev_xfermask(struct ata_device *dev)
 				       dev->mwdma_mask, dev->udma_mask);
 	xfer_mask &= ata_id_xfermask(dev->id);
 
+	if (ata_debug_cocktail & (1 << 0)) {
+		int i;
+
+		/* PIO xfermask limits are shared by all devices on the same
+		 * channel to avoid violating device selection timing.
+		 */
+		ata_dev_printk(dev, KERN_INFO, "XXX common PIO mode: pre: %lx\n",
+			       xfer_mask);
+		for (i = 0; i < ATA_MAX_DEVICES; i++) {
+			struct ata_device *d = &ap->device[i];
+			unsigned int pio_mask;
+
+			if (ata_dev_absent(d))
+				continue;
+
+			ata_unpack_xfermask(ata_id_xfermask(d->id),
+					    &pio_mask, NULL, NULL);
+			pio_mask &= d->pio_mask;
+			xfer_mask &= ata_pack_xfermask(pio_mask, UINT_MAX, UINT_MAX);
+		}
+		ata_dev_printk(dev, KERN_INFO, "XXX common PIO mode: post: %lx\n",
+			       xfer_mask);
+	}
 	/*
 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
 	 *	cable
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 7645f2b..5bb5bd4 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -39,6 +39,51 @@
 #include "libata.h"
 
 /**
+ *	ata_irq_on - Enable interrupts on a port.
+ *	@ap: Port on which interrupts are enabled.
+ *
+ *	Enable interrupts on a legacy IDE device using MMIO or PIO,
+ *	wait for idle, clear any pending interrupts.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+u8 ata_irq_on(struct ata_port *ap)
+{
+	struct ata_ioports *ioaddr = &ap->ioaddr;
+	u8 tmp;
+
+	ap->ctl &= ~ATA_NIEN;
+	ap->last_ctl = ap->ctl;
+
+	if (ata_debug_cocktail & (1 << 2)) {
+		ata_port_printk(ap, KERN_INFO, "XXX clear NIEN on both devices\n");
+		ap->ops->dev_select(ap, 1);
+	}
+	if (ap->flags & ATA_FLAG_MMIO)
+		writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
+	else
+		outb(ap->ctl, ioaddr->ctl_addr);
+	tmp = ata_wait_idle(ap);
+
+	if (ata_debug_cocktail & (1 << 2)) {
+		ap->ops->dev_select(ap, 0);
+		if (ap->flags & ATA_FLAG_MMIO)
+			writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
+		else
+			outb(ap->ctl, ioaddr->ctl_addr);
+		tmp = ata_wait_idle(ap);
+	}
+
+	ap->ops->irq_clear(ap);
+
+	return tmp;
+}
+
+
+
+/**
  *	ata_tf_load_pio - send taskfile registers to host controller
  *	@ap: Port to which output is sent
  *	@tf: ATA taskfile register set
@@ -664,6 +709,10 @@ void ata_bmdma_freeze(struct ata_port *ap)
 {
 	struct ata_ioports *ioaddr = &ap->ioaddr;
 
+	if (ata_debug_cocktail & (1 << 3)) {
+		ata_port_printk(ap, KERN_INFO, "XXX skipping BMDMA freeze\n");
+		return;
+	}
 	ap->ctl |= ATA_NIEN;
 	ap->last_ctl = ap->ctl;
 
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 0ed263b..9868965 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -43,6 +43,7 @@ extern struct workqueue_struct *ata_aux_wq;
 extern int atapi_enabled;
 extern int atapi_dmadir;
 extern int libata_fua;
+extern int ata_debug_cocktail;
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
 extern int ata_rwcmd_protocol(struct ata_queued_cmd *qc);
 extern void ata_dev_disable(struct ata_device *dev);
@@ -120,4 +121,7 @@ extern void ata_scsi_error(struct Scsi_Host *host);
 extern void ata_port_wait_eh(struct ata_port *ap);
 extern void ata_qc_schedule_eh(struct ata_queued_cmd *qc);
 
+/* libata-sff.c */
+extern u8 ata_irq_on(struct ata_port *ap);
+
 #endif /* __LIBATA_H__ */
diff --git a/include/linux/libata.h b/include/linux/libata.h
index abd2deb..bc36068 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1148,37 +1148,6 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
 }
 
 /**
- *	ata_irq_on - Enable interrupts on a port.
- *	@ap: Port on which interrupts are enabled.
- *
- *	Enable interrupts on a legacy IDE device using MMIO or PIO,
- *	wait for idle, clear any pending interrupts.
- *
- *	LOCKING:
- *	Inherited from caller.
- */
-
-static inline u8 ata_irq_on(struct ata_port *ap)
-{
-	struct ata_ioports *ioaddr = &ap->ioaddr;
-	u8 tmp;
-
-	ap->ctl &= ~ATA_NIEN;
-	ap->last_ctl = ap->ctl;
-
-	if (ap->flags & ATA_FLAG_MMIO)
-		writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
-	else
-		outb(ap->ctl, ioaddr->ctl_addr);
-	tmp = ata_wait_idle(ap);
-
-	ap->ops->irq_clear(ap);
-
-	return tmp;
-}
-
-
-/**
  *	ata_irq_ack - Acknowledge a device interrupt.
  *	@ap: Port on which interrupts are enabled.
  *