From: Michael Trimarchi Date: Mon, 18 Mar 2019 09:47:45 +0000 (+0530) Subject: sunxi: dram_sun8i: Fix A33 memory initialization X-Git-Tag: v2019.07-rc1~28^2~4 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=ddd693021535b2ebd434b712c90443d95728cc8f;p=oweals%2Fu-boot.git 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 Signed-off-by: Shyam Saini Acked-by: Jagan Teki --- 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)