diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/cpu/armv7/sunxi/dram.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm/cpu/armv7/sunxi/dram.c b/arch/arm/cpu/armv7/sunxi/dram.c index dc79d1c..a632926 100644 --- a/arch/arm/cpu/armv7/sunxi/dram.c +++ b/arch/arm/cpu/armv7/sunxi/dram.c @@ -48,6 +48,11 @@ static void await_completion(u32 *reg, u32 mask) } } +/* + * This performs the external DRAM reset by driving the RESET pin low and + * then high again. According to the DDR3 spec, the RESET pin needs to be + * kept low for at least 200 us. + */ static void mctl_ddr3_reset(void) { struct sunxi_dram_reg *dram = @@ -64,13 +69,13 @@ static void mctl_ddr3_reset(void) if ((reg_val & CPU_CFG_CHIP_VER_MASK) != CPU_CFG_CHIP_VER(CPU_CFG_CHIP_REV_A)) { setbits_le32(&dram->mcr, DRAM_MCR_RESET); - udelay(2); + udelay(200); clrbits_le32(&dram->mcr, DRAM_MCR_RESET); } else #endif { clrbits_le32(&dram->mcr, DRAM_MCR_RESET); - udelay(2); + udelay(200); setbits_le32(&dram->mcr, DRAM_MCR_RESET); } } |