[Patch] i386: remove 'usedac' kernel parameter

[Amerigo Wang <amwang@redhat.com>]

It is scheduled to be removed.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Glauber Costa <gcosta@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>

---
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 591e944..8c895f6 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -291,13 +291,6 @@ Who:	Michael Buesch <mb@bu3sch.de>
 
 ---------------------------
 
-What:	usedac i386 kernel parameter
-When:	2.6.27
-Why:	replaced by allowdac and no dac combination
-Who:	Glauber Costa <gcosta@redhat.com>
-
----------------------------
-
 What: print_fn_descriptor_symbol()
 When: October 2009
 Why:  The %pF vsprintf format provides the same functionality in a
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index afcc58b..2f76c7b 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -210,10 +210,6 @@ static __init int iommu_setup(char *p)
 			forbid_dac = 0;
 		if (!strncmp(p, "nodac", 5))
 			forbid_dac = 1;
-		if (!strncmp(p, "usedac", 6)) {
-			forbid_dac = -1;
-			return 1;
-		}
 #ifdef CONFIG_SWIOTLB
 		if (!strncmp(p, "soft", 4))
 			swiotlb = 1;