commit 2a0adceb5029c8ee633d17c82dbb11e48d30349d
author Gabe Black <gabeblack@google.com> Mon Sep 30 05:08:23 2013 -0700
committer chrome-internal-fetch <chrome-internal-fetch@google.com> Tue Oct 01 08:16:15 2013 +0000
tree 95e39165ea03311a936acebdbc2e2a5e5b13f4e0
parent 65f1aa116b0f7d4fa7af24cfe1c441f8fd16c6d3

tegra124: Re-enable waiting for the transmitter to empty in the test function.

The compiler was emitting code compatible with armv7-a, but the bootblock was
running on a core which uses armv4t. By coincidence, it was emitting an
instruction which is unavailable on armv4t when checking the value of the
UART's LSR register. Now that the bootblock is compiled with more appropriate
flags, this code can be re-introduced.

BUG=None
TEST=Built into the bootblock on nyan and, with the test function enabled, saw
a stream of "!"s on the console.
BRANCH=None

Change-Id: I7ecada4138b0889b963d1a8b19a4bab8e0bb1add
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/170997
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>

src/soc/nvidia/tegra124/bootblock.c

diff --git a/src/soc/nvidia/tegra124/bootblock.c b/src/soc/nvidia/tegra124/bootblock.c
index 46997b9..fb5ddea 100644
--- a/src/soc/nvidia/tegra124/bootblock.c
+++ b/src/soc/nvidia/tegra124/bootblock.c
@@ -83,10 +83,7 @@
 	// De-assert reset to UART.
 	clrbits_le32((void *)(0x60006000 + 4 + 0), 1 << 6);
 
-	// This is supposed to wait for the transmitter to be empty, but it
-	// never completes for some reason.
-	if (0)
-		while (!(readr(5) & 0x40));
+	while (!(readr(5) & 0x40));
 
 	writer(1, 0);
 	writer(3, 0x80 | 0x3);