[U-Boot] [PATCH] arm: ls1021atwr: optimize the deep sleep latency

[Tang Yuantian]

It will take more than 1s when wake up from deep sleep. Most of the
time is spent on outputing information. This patch reduced the deep
sleep latency by:
1. avoid outputing system informaton
2. remove flush cache after DDR restore
3. skip reloading second stage uboot binary when SD boot

Signed-off-by: Tang Yuantian <Yuantian.Tang at freescale.com>
---
 board/freescale/common/arm_sleep.c      |  4 ----
 board/freescale/ls1021atwr/ls1021atwr.c | 19 +++++++++++++++++--
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/board/freescale/common/arm_sleep.c b/board/freescale/common/arm_sleep.c
index 8e8b7fa..a498c65 100644
--- a/board/freescale/common/arm_sleep.c
+++ b/board/freescale/common/arm_sleep.c
@@ -12,7 +12,6 @@
 #include <asm/secure.h>
 #endif
 #include <asm/armv7.h>
-#include <asm/cache.h>
 
 #if defined(CONFIG_LS102XA)
 #include <asm/arch/immap_ls102xa.h>
@@ -65,8 +64,6 @@ static void dp_ddr_restore(void)
 
 	for (i = 0; i < DDR_BUFF_LEN / 8; i++)
 		*dst++ = *src++;
-
-	flush_dcache_all();
 }
 
 static void dp_resume_prepare(void)
@@ -74,7 +71,6 @@ static void dp_resume_prepare(void)
 	dp_ddr_restore();
 	board_sleep_prepare();
 	armv7_init_nonsec();
-	cleanup_before_linux();
 #ifdef CONFIG_U_QE
 	u_qe_resume();
 #endif
diff --git a/board/freescale/ls1021atwr/ls1021atwr.c b/board/freescale/ls1021atwr/ls1021atwr.c
index 228dbf8..236376b 100644
--- a/board/freescale/ls1021atwr/ls1021atwr.c
+++ b/board/freescale/ls1021atwr/ls1021atwr.c
@@ -521,8 +521,10 @@ int board_early_init_f(void)
 	}
 
 #if defined(CONFIG_DEEP_SLEEP)
-	if (is_warm_boot())
-		fsl_dp_disable_console();
+	if (is_warm_boot()) {
+		timer_init();
+		dram_init();
+	}
 #endif
 
 	return 0;
@@ -531,6 +533,8 @@ int board_early_init_f(void)
 #ifdef CONFIG_SPL_BUILD
 void board_init_f(ulong dummy)
 {
+	void (*second_uboot)(void);
+
 	/* Clear the BSS */
 	memset(__bss_start, 0, __bss_end - __bss_start);
 
@@ -551,6 +555,17 @@ void board_init_f(ulong dummy)
 	enable_devices_ns_access(&ns_dev[7], 1);
 #endif
 
+	/*
+	 * if it is woken up from deep sleep, then jump to second
+	 * stage uboot and continue executing without recopying
+	 * it from SD since it has already been reserved in memeory
+	 * in last boot.
+	 */
+	if (is_warm_boot()) {
+		second_uboot = (void (*)(void))CONFIG_SYS_TEXT_BASE;
+		second_uboot();
+	}
+
 	board_init_r(NULL, 0);
 }
 #endif
-- 
2.1.0.27.g96db324