--- kernel/drivers/ide/ide-dma.c	2006-08-20 11:31:53.000000000 +0200
+++ kernel/drivers/ide/ide-dma.c	2006-08-20 11:40:43.000000000 +0200
@@ -89,6 +89,57 @@
 #include <asm/io.h>
 #include <asm/irq.h>
 
+
+/* Some VIA boards show strange slowdown when HLT is eanbled  */
+/* So we disable the HLT during a IDE-DMA transfer.           */
+/* You need to pass disableviahlt at boottime to enable this  */
+/* workaround.                                                */
+#if defined(HAVE_DISABLE_HLT)
+
+static DEFINE_SPINLOCK(ide_hlt_lock);
+static int hlt_disabled;
+static int disableviahlt;
+static void ide_disable_hlt(void)
+{
+	unsigned long flags;
+	
+	spin_lock_irqsave(&ide_hlt_lock, flags);
+	if(disableviahlt) {
+		hlt_disabled++ ;
+		disable_hlt();
+	}
+	spin_unlock_irqrestore(&ide_hlt_lock, flags);
+}
+
+static void ide_enable_hlt(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ide_hlt_lock, flags);
+	if(hlt_disabled && disableviahlt){
+		hlt_disabled--;
+		enable_hlt();
+	}
+	spin_unlock_irqrestore(&ide_hlt_lock, flags);
+}
+
+static int __init disable_via_hlt(char *str)
+{
+    printk(KERN_WARNING "DISABLE VIA HLT  activated\n");
+    disableviahlt = 1;
+    return 1;
+}
+
+__setup("disableviahlt", disable_via_hlt);
+
+
+#else  /* HAVE_DISABLE_HLT */
+inline static void ide_disable_hlt(void)
+{}
+inline static void ide_enable_hlt(void)
+{}
+#endif /* HAVE_DISABLE_HLT */
+
 static const struct drive_list_entry drive_whitelist [] = {
 
 	{ "Micropolis 2112A"	,       "ALL"		},
@@ -301,6 +352,7 @@
 	if (count) {
 		if (!is_trm290)
 			*--table |= cpu_to_le32(0x80000000);
+		ide_disable_hlt();
 		return count;
 	}
 	printk(KERN_ERR "%s: empty DMA table?\n", drive->name);
@@ -332,6 +384,7 @@
 	int nents = HWIF(drive)->sg_nents;
 
 	pci_unmap_sg(dev, sg, nents, HWIF(drive)->sg_dma_direction);
+	ide_enable_hlt();
 }
 
 EXPORT_SYMBOL_GPL(ide_destroy_dmatable);