From 2a5d5d27edfbdb0e02a7fcf05569f92c02ae44ee Mon Sep 17 00:00:00 2001 From: Joakim Tjernlund Date: Wed, 27 Nov 2019 19:35:10 +0100 Subject: [PATCH] mpc85xx: ddr: Always start DDR RAM in Self Refresh mode Some of t1042 boards fails DDR init with an Automatic calibration error every now and then. Investigations revealed that true Warm boots never failed. Warm boots has some extra steps performed, one being to start DDRC in Self Refresh and then clearing SR right after. Applying this SR method unconditionally made all our boards stable again, regardless of Cold/Warm boot. Signed-off-by: Joakim Tjernlund Signed-off-by: Priyanka Jain --- drivers/ddr/fsl/mpc85xx_ddr_gen3.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/ddr/fsl/mpc85xx_ddr_gen3.c b/drivers/ddr/fsl/mpc85xx_ddr_gen3.c index a9b085d..952b296 100644 --- a/drivers/ddr/fsl/mpc85xx_ddr_gen3.c +++ b/drivers/ddr/fsl/mpc85xx_ddr_gen3.c @@ -370,6 +370,8 @@ step2: debug("Setting DEBUG_3[21] to 0x%08x\n", in_be32(&ddr->debug[2])); #endif /* part 1 of the workaound */ + /* Always start in self-refresh, clear after MEM_EN */ + setbits_be32(&ddr->sdram_cfg_2, SDRAM_CFG2_FRC_SR); /* * 500 painful micro-seconds must elapse between @@ -382,8 +384,6 @@ step2: #ifdef CONFIG_DEEP_SLEEP if (is_warm_boot()) { - /* enter self-refresh */ - setbits_be32(&ddr->sdram_cfg_2, SDRAM_CFG2_FRC_SR); /* do board specific memory setup */ board_mem_sleep_setup(); temp_sdram_cfg = (in_be32(&ddr->sdram_cfg) | SDRAM_CFG_BI); @@ -395,6 +395,10 @@ step2: out_be32(&ddr->sdram_cfg, temp_sdram_cfg | SDRAM_CFG_MEM_EN); asm volatile("sync;isync"); + /* Exit self-refresh after DDR conf as some ddr memories can fail. */ + clrbits_be32(&ddr->sdram_cfg_2, SDRAM_CFG2_FRC_SR); + asm volatile("sync;isync"); + total_gb_size_per_controller = 0; for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) { if (!(regs->cs[i].config & 0x80000000)) @@ -544,9 +548,4 @@ step2: clrbits_be32(&ddr->sdram_cfg, 0x2); } #endif /* CONFIG_SYS_FSL_ERRATUM_DDR111_DDR134 */ -#ifdef CONFIG_DEEP_SLEEP - if (is_warm_boot()) - /* exit self-refresh */ - clrbits_be32(&ddr->sdram_cfg_2, SDRAM_CFG2_FRC_SR); -#endif } -- 2.7.4