From ba4e159f9804c02a87ed38be0ed669a348d78f25 Mon Sep 17 00:00:00 2001
From: Fabio Estevam <fabio.estevam@nxp.com>
Date: Mon, 12 Sep 2016 11:38:36 -0300
Subject: [PATCH] wandboard: Fix hang when going into low frequency
A kernel hang is observed when running wandboard 3.14 kernel and
going to the lowest operational point of cpufreq:
# ifconfig eth0 down
# echo 1 > /sys/class/graphics/fb0/blank
The problem is caused by incorrect setting of the REFR field
of register MDREF. Setting it to 4 refresh commands per refresh
cycle fixes the hang.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
---
board/wandboard/spl.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/board/wandboard/spl.c b/board/wandboard/spl.c
index c513b22d82..a21a3d0f21 100644
--- a/board/wandboard/spl.c
+++ b/board/wandboard/spl.c
@@ -188,7 +188,7 @@ static struct mx6_ddr_sysinfo mem_q = {
.rst_to_cke = 0x23,
.sde_to_rst = 0x10,
.refsel = 1, /* Refresh cycles at 32KHz */
- .refr = 7, /* 8 refresh commands per refresh cycle */
+ .refr = 3, /* 4 refresh commands per refresh cycle */
};
static struct mx6_mmdc_calibration mx6dl_1g_mmdc_calib = {
@@ -231,7 +231,7 @@ static struct mx6_ddr_sysinfo mem_dl = {
.rst_to_cke = 0x23,
.sde_to_rst = 0x10,
.refsel = 1, /* Refresh cycles at 32KHz */
- .refr = 7, /* 8 refresh commands per refresh cycle */
+ .refr = 3, /* 4 refresh commands per refresh cycle */
};
/* DDR 32bit 512MB */
@@ -250,7 +250,7 @@ static struct mx6_ddr_sysinfo mem_s = {
.rst_to_cke = 0x23,
.sde_to_rst = 0x10,
.refsel = 1, /* Refresh cycles at 32KHz */
- .refr = 7, /* 8 refresh commands per refresh cycle */
+ .refr = 3, /* 4 refresh commands per refresh cycle */
};
static void ccgr_init(void)
--
2.39.5