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mx6ul_14x14_evk: Pass refsel and refr fields to avoid hang 

When running a NXP 4.1 kernel with U-Boot mainline on a mx6ul-evk,
we observe a hang when going into the lowest operational point of cpufreq.

This hang issue does not happen on the NXP U-Boot version.

After comparing the SPL DDR initialization against the DCD table
from NXP U-Boot, the key difference that causes the hang is the
MDREF register setting:

DATA 4 0x021B0020 0x00000800

,which means:

REF_SEL = 0 --> Periodic refresh cycle: 64kHz
REFR = 1 ---> Refresh Rate - 2 refreshes

So adjust the MDREF initialization for mx6ul_evk accordingly
to fix the kernel hang issue at low bus frequency.

Reported-by: Eric Nelson <eric@nelint.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Eric Nelson <eric@nelint.com>
This commit is contained in:
Fabio Estevam 2016-08-29 20:37:16 -03:00 committed by Stefano Babic
parent edf0093732
commit 7dbda25ecd
1 changed files with 2 additions and 2 deletions
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4
board/freescale/mx6ul_14x14_evk/mx6ul_14x14_evk.c
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@ -804,8 +804,8 @@ struct mx6_ddr_sysinfo ddr_sysinfo = {
.sde_to_rst = 0x10, /* 14 cycles, 200us (JEDEC default) */
.rst_to_cke = 0x23, /* 33 cycles, 500us (JEDEC default) */
.ddr_type = DDR_TYPE_DDR3,
.refsel = 1, /* Refresh cycles at 32KHz */
.refr = 7, /* 8 refresh commands per refresh cycle */
.refsel = 0, /* Refresh cycles at 64KHz */
.refr = 1, /* 2 refresh commands per refresh cycle */
};
static struct mx6_ddr3_cfg mem_ddr = {