From 89e45f8352f62e19a203316330aba14ccc5c8b11 Mon Sep 17 00:00:00 2001
From: Lin Huang <hl@rock-chips.com>
Date: Mon, 10 Oct 2016 20:57:09 -0700
Subject: [PATCH] rockchip/rk3399: reset system if ddr initial fail

we found sdram may fail in pctl_cfg() function, so we check the status
in this function, if exceed 100ms still in this function, we will restart
the system, we also found there are rare chance fail in ddr training, also
restart system if ddr training fail.

BUG=chrome-os-partner:57988
BRANCH=None
TEST=reset in coreboot, and never happen it again

Change-Id: If4e78983abcfdfe1e0e26847448d86169e598700
Signed-off-by: Lin Huang <hl@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/397439
Reviewed-by: Julius Werner <jwerner@chromium.org>
---
 src/mainboard/google/gru/Makefile.inc |  1 +
 src/soc/rockchip/rk3399/sdram.c       | 36 +++++++++++++++++++++------
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/src/mainboard/google/gru/Makefile.inc b/src/mainboard/google/gru/Makefile.inc
index 034edde8a7..122139dd15 100644
--- a/src/mainboard/google/gru/Makefile.inc
+++ b/src/mainboard/google/gru/Makefile.inc
@@ -31,6 +31,7 @@ romstage-y += chromeos.c
 romstage-y += memlayout.ld
 romstage-y += pwm_regulator.c
 romstage-y += romstage.c
+romstage-y += reset.c
 romstage-y += sdram_configs.c
 
 ramstage-y += boardid.c
diff --git a/src/soc/rockchip/rk3399/sdram.c b/src/soc/rockchip/rk3399/sdram.c
index 42b2574746..d543801cda 100644
--- a/src/soc/rockchip/rk3399/sdram.c
+++ b/src/soc/rockchip/rk3399/sdram.c
@@ -16,12 +16,14 @@
 #include <arch/io.h>
 #include <console/console.h>
 #include <delay.h>
+#include <reset.h>
 #include <soc/addressmap.h>
 #include <soc/clock.h>
 #include <soc/sdram.h>
 #include <soc/grf.h>
 #include <soc/soc.h>
 #include <string.h>
+#include <timer.h>
 #include <types.h>
 
 #define DDR_PI_OFFSET			0x800
@@ -466,8 +468,8 @@ static void phy_io_config(u32 channel,
 	clrsetbits_le32(&denali_phy[939], 0x3 << 17, speed << 17);
 }
 
-static void pctl_cfg(u32 channel,
-		     const struct rk3399_sdram_params *sdram_params)
+static int pctl_cfg(u32 channel,
+		    const struct rk3399_sdram_params *sdram_params)
 {
 	u32 *denali_ctl = rk3399_ddr_pctl[channel]->denali_ctl;
 	u32 *denali_pi = rk3399_ddr_pi[channel]->denali_pi;
@@ -476,6 +478,7 @@ static void pctl_cfg(u32 channel,
 	const u32 *params_phy = sdram_params->phy_regs.denali_phy;
 	u32 tmp, tmp1, tmp2;
 	u32 pwrup_srefresh_exit;
+	struct stopwatch sw;
 
 	/*
 	 * work around controller bug:
@@ -556,12 +559,18 @@ static void pctl_cfg(u32 channel,
 
 	/*
 	 * FIXME:
-	 * need to care ERROR bit
+	 * need to care ERROR bit,
+	 * if 100ms do not get right status, return err
 	 */
-	while (!(read32(&denali_ctl[203]) & (1 << 3)))
-		;
+	stopwatch_init_msecs_expire(&sw, 100);
+	while (!(read32(&denali_ctl[203]) & (1 << 3))) {
+		if (stopwatch_expired(&sw))
+			return -1;
+	}
+
 	clrsetbits_le32(&denali_ctl[68], PWRUP_SREFRESH_EXIT,
 			pwrup_srefresh_exit);
+	return 0;
 }
 
 static void select_per_cs_training_index(u32 channel, u32 rank)
@@ -987,14 +996,25 @@ void sdram_init(const struct rk3399_sdram_params *sdram_params)
 		if (channel >= sdram_params->num_channels)
 			continue;
 
-		pctl_cfg(channel, sdram_params);
+		/*
+		 * TODO: we need to find the root cause why this
+		 * step may fail, before that, we just reset the
+		 * system, and start again.
+		 */
+		if (pctl_cfg(channel, sdram_params) != 0) {
+			printk(BIOS_ERR, "pctl_cfg fail, reset\n");
+			hard_reset();
+		}
 
 		/* LPDDR2/LPDDR3 need to wait DAI complete, max 10us */
 		if (dramtype == LPDDR3)
 			udelay(10);
 
-		if (data_training(channel, sdram_params, PI_FULL_TARINING))
-			die("SDRAM initialization failed!");
+		if (data_training(channel, sdram_params, PI_FULL_TARINING)) {
+			printk(BIOS_DEBUG,
+			       "SDRAM initialization failed, reset\n");
+			hard_reset();
+		}
 
 		set_ddrconfig(sdram_params, channel,
 			      sdram_params->ch[channel].ddrconfig);