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Hang up when write MMDC->MDSCR in write leveling function.

Question asked by Takayuki Ishii on Aug 21, 2019
Latest reply on Aug 29, 2019 by gusarambula
Branched to a new discussion

Hello community,

 

I try to do write leveling in Plugin Image of u-boot for imx6qp Android BSP N7.1.2_2.0.0-ga.

So make assembler macro "mx6_write_level_calibration" based on the "int mmdc_do_write_level_calibration()"

in the arch/arm/cpu/armv7/mx6.

And call it from arch/arm/include/asm/arch-mx6/mx6_plugin.S

 

plugin_loop:
      nop
      b plugin_loop    /* to connect debug session */
      nop
      imx6_ddr_setting
      imx6_clock_gating
      imx6_qos_setting
      mx6_write_level_calibration

 

In Write leveling sequence, after write mmcd0->mdscr register to configure the external DDR device to enter

write-leveling mode through Load Mode Register command.

 

/* writel(0x00808231, &mmdc0->mdscr); */

 

i.MX6QP will hang-up and JTAG debug session is stopping.

 

To send Load Mode Register command, do I need some other setting?

 

Best regards,

Ishii.

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