[PATCH 1/1] sunxi: dram: Fix incorrect ram size detection for some H6 boards

[Gunjan Gupta <viraniac@gmail.com>]

On some H6 boards like Orange Pi 3 LTS, some times U-Boot fails to detect
ram size correctly. Instead of 2GB thats available, it detects 4GB of ram
and then SPL just hangs there making board not to boot further.

On debugging, I found that the rows value were being determined correctly,
but columns were sometimes off by one value. I found that adding some
delay after the mctl_core_init call along with making use of dsb in the
start of the mctl_mem_matches solves the issue.

Signed-off-by: Gunjan Gupta <viraniac@gmail.com>
---

 arch/arm/mach-sunxi/dram_helpers.c   | 1 +
 arch/arm/mach-sunxi/dram_sun50i_h6.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/arch/arm/mach-sunxi/dram_helpers.c b/arch/arm/mach-sunxi/dram_helpers.c
index cdf2750f1c..5758c58e07 100644
--- a/arch/arm/mach-sunxi/dram_helpers.c
+++ b/arch/arm/mach-sunxi/dram_helpers.c
@@ -32,6 +32,7 @@ void mctl_await_completion(u32 *reg, u32 mask, u32 val)
 #ifndef CONFIG_MACH_SUNIV
 bool mctl_mem_matches(u32 offset)
 {
+	dsb();
 	/* Try to write different values to RAM at two addresses */
 	writel(0, CFG_SYS_SDRAM_BASE);
 	writel(0xaa55aa55, (ulong)CFG_SYS_SDRAM_BASE + offset);
diff --git a/arch/arm/mach-sunxi/dram_sun50i_h6.c b/arch/arm/mach-sunxi/dram_sun50i_h6.c
index bff2e42513..a031a845f5 100644
--- a/arch/arm/mach-sunxi/dram_sun50i_h6.c
+++ b/arch/arm/mach-sunxi/dram_sun50i_h6.c
@@ -623,6 +623,8 @@ static void mctl_auto_detect_dram_size(struct dram_para *para)
 	para->cols = 11;
 	mctl_core_init(para);
 
+	udelay(50);
+
 	for (para->cols = 8; para->cols < 11; para->cols++) {
 		/* 8 bits per byte and 16/32 bit width */
 		if (mctl_mem_matches(1 << (para->cols + 1 +
-- 
2.42.0