From 10fcabed8857d2c12a5806c68cf884802f975aae Mon Sep 17 00:00:00 2001
From: Bin Meng <bmeng.cn@gmail.com>
Date: Wed, 11 May 2016 07:45:05 -0700
Subject: x86: acpi: Remove header length check when writing tables

Before moving 'current' pointer during ACPI table writing, we always
check the table length to see if it is larger than the table header.
Since our purpose is to generate valid tables, the check logic is
always true, which can be avoided.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
index 1c57094..ffb4678 100644
--- a/arch/x86/lib/acpi_table.c
+++ b/arch/x86/lib/acpi_table.c
@@ -376,13 +376,11 @@ u32 write_acpi_tables(u32 start)
 	debug("ACPI:    * DSDT\n");
 	dsdt = (struct acpi_table_header *)current;
 	memcpy(dsdt, &AmlCode, sizeof(struct acpi_table_header));
-	if (dsdt->length >= sizeof(struct acpi_table_header)) {
-		current += sizeof(struct acpi_table_header);
-		memcpy((char *)current,
-			(char *)&AmlCode + sizeof(struct acpi_table_header),
-			dsdt->length - sizeof(struct acpi_table_header));
-		current += dsdt->length - sizeof(struct acpi_table_header);
-	}
+	current += sizeof(struct acpi_table_header);
+	memcpy((char *)current,
+	       (char *)&AmlCode + sizeof(struct acpi_table_header),
+	       dsdt->length - sizeof(struct acpi_table_header));
+	current += dsdt->length - sizeof(struct acpi_table_header);
 	current = ALIGN(current, 16);
 
 	debug("ACPI:    * FADT\n");
@@ -395,20 +393,16 @@ u32 write_acpi_tables(u32 start)
 	debug("ACPI:    * MADT\n");
 	madt = (struct acpi_madt *)current;
 	acpi_create_madt(madt);
-	if (madt->header.length > sizeof(struct acpi_madt)) {
-		current += madt->header.length;
-		acpi_add_table(rsdp, madt);
-	}
+	current += madt->header.length;
+	acpi_add_table(rsdp, madt);
 	current = ALIGN(current, 16);
 
 	debug("ACPI:    * MCFG\n");
 	mcfg = (struct acpi_mcfg *)current;
 	acpi_create_mcfg(mcfg);
-	if (mcfg->header.length > sizeof(struct acpi_mcfg)) {
-		current += mcfg->header.length;
-		current = ALIGN(current, 16);
-		acpi_add_table(rsdp, mcfg);
-	}
+	current += mcfg->header.length;
+	acpi_add_table(rsdp, mcfg);
+	current = ALIGN(current, 16);
 
 	debug("current = %x\n", current);
 
-- 
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