From: Mike Frysinger <michael.frysinger@analog.com>
Date: Mon, 21 May 2007 10:09:27 +0000 (+0800)
Subject: Blackfin arch: document why we have to touch the UART peripheral in our boot up code
X-Git-Tag: v2.6.22-rc3~138
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5079df993c3ab45af10dc9a45b3b9e712fd56f23;p=platform%2Fupstream%2Fkernel-adaptation-pc.git

Blackfin arch: document why we have to touch the UART peripheral in our boot up code

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/blackfin/mach-bf533/head.S b/arch/blackfin/mach-bf533/head.S
index 1a54ff5..4db9e62 100644
--- a/arch/blackfin/mach-bf533/head.S
+++ b/arch/blackfin/mach-bf533/head.S
@@ -173,7 +173,8 @@ ENTRY(__stext)
 	STI R2;
 #endif
 
-	/* Initialise UART */
+	/* Initialise UART - when booting from u-boot, the UART is not disabled
+	 * so if we dont initalize here, our serial console gets hosed */
 	p0.h = hi(UART_LCR);
 	p0.l = lo(UART_LCR);
 	r0 = 0x0(Z);
diff --git a/arch/blackfin/mach-bf537/head.S b/arch/blackfin/mach-bf537/head.S
index aafc686..b4377dd 100644
--- a/arch/blackfin/mach-bf537/head.S
+++ b/arch/blackfin/mach-bf537/head.S
@@ -181,7 +181,8 @@ ENTRY(__stext)
 	SSYNC;
 #endif
 
-	/*Initialise UART*/
+	/* Initialise UART - when booting from u-boot, the UART is not disabled
+	 * so if we dont initalize here, our serial console gets hosed */
 	p0.h = hi(UART_LCR);
 	p0.l = lo(UART_LCR);
 	r0 = 0x0(Z);
diff --git a/arch/blackfin/mach-bf561/head.S b/arch/blackfin/mach-bf561/head.S
index 04f3ac3..9c8e688 100644
--- a/arch/blackfin/mach-bf561/head.S
+++ b/arch/blackfin/mach-bf561/head.S
@@ -127,7 +127,8 @@ ENTRY(__stext)
 	STI R2;
 #endif
 
-	/* Initialise UART*/
+	/* Initialise UART - when booting from u-boot, the UART is not disabled
+	 * so if we dont initalize here, our serial console gets hosed */
 	p0.h = hi(UART_LCR);
 	p0.l = lo(UART_LCR);
 	r0 = 0x0(Z);