diff options
| author | Michael Trimarchi <michael@amarulasolutions.com> | 2019-03-18 15:17:45 +0530 |
|---|---|---|
| committer | Jagan Teki <jagan@amarulasolutions.com> | 2019-04-10 15:32:59 +0530 |
| commit | ddd693021535b2ebd434b712c90443d95728cc8f (patch) | |
| tree | ea580f0a158da554c242ca2b7f856f384bdb7e37 /arch/arm/mach-sunxi | |
| parent | 30cb441ec69838cffe211cfde6ff6f7fa5a395cd (diff) | |
sunxi: dram_sun8i: Fix A33 memory initialization
While the exact problem is not known, based on discussion between
Philipp Tomsich and André Przywara it is guessed that exit self-refresh
timing is not set with correct value. There may be implicit enter or
exit Self-Refresh anywhere as part of some training phase.
In ZynqMP register guide [1], which is close to the various
Allwinner DRAM controllers, tXSDLL is bits [14:8], while the non-DLL
tXS is bits [6:0]: Self refresh exit delay. So it could be safely
increased and it only affects the time after the self-refresh “exit”,
which happens only after (re-)initialisation.
There was no document for cpu in question so based on oscilloscope
readings [2][3] and observed result by comparing allwinner architecture.
So set it same as Allwinner H5 silicon.
Before this patch, failure rate of was 7%.
This was tested on A33 allwinner cpu, dual rank connection connected
with two MT41K512M16HA-125:A memory model. Memory is configured as DDR3
1.5V
And also this is tested in A33-OLinuXino dev board.
[1] https://www.xilinx.com/html_docs/registers/ug1087/ddrc___dramtmg8.html
[2] https://ibb.co/R70zmyS
[3] https://ibb.co/HVVCGQ8
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Shyam Saini <shyam.saini@amarulasolutions.com>
Acked-by: Jagan Teki <jagan@openedev.com>
Diffstat (limited to 'arch/arm/mach-sunxi')
| -rw-r--r-- | arch/arm/mach-sunxi/dram_sun8i_a33.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mach-sunxi/dram_sun8i_a33.c b/arch/arm/mach-sunxi/dram_sun8i_a33.c index 1da2727f98..5da01922bf 100644 --- a/arch/arm/mach-sunxi/dram_sun8i_a33.c +++ b/arch/arm/mach-sunxi/dram_sun8i_a33.c @@ -152,7 +152,7 @@ static void auto_set_timing_para(struct dram_para *para) reg_val &= ~(0xff << 8); reg_val &= ~(0xff << 0); reg_val |= (0x33 << 8); - reg_val |= (0x8 << 0); + reg_val |= (0x10 << 0); writel(reg_val, &mctl_ctl->dramtmg8); /* Set phy interface time */ reg_val = (0x2 << 24) | (t_rdata_en << 16) | (0x1 << 8) |