Help with u-boot when using the eMMC card in DDR mode

[Abder]

Hi Jaehoon,
This is the output with MMC_TRACE enabled

U-Boot >mmc dev 2
blk_find_device: if_type=6, devnum=2: usdhc at 02198000.blk, 6, 2
ofnode_read_u32: vmmc-supply: 0x33 (51)
ofnode_read_u32: vqmmc-supply: 0x33 (51)
clock is disabled (0Hz)
fixed_regulator_set_enable: dev='3p3v', enable=1, delay=0, has_gpio=0
clock is enabled (400000Hz)
CMD_SEND:0
                ARG                      0x00000000
                MMC_RSP_NONE
CMD_SEND:8
                ARG                      0x000001aa
                RET                      -110
CMD_SEND:55
                ARG                      0x00000000
                RET                      -110
CMD_SEND:0
                ARG                      0x00000000
                MMC_RSP_NONE
CMD_SEND:1
                ARG                      0x00000000
                MMC_RSP_R3,4             0x00ff8080
CMD_SEND:1
                ARG                      0x40300000
                MMC_RSP_R3,4             0x00ff8080
CMD_SEND:0
                ARG                      0x00000000
                MMC_RSP_NONE
CMD_SEND:1
                ARG                      0x40300000
                MMC_RSP_R3,4             0x00ff8080
CMD_SEND:1
                ARG                      0x40300000
                MMC_RSP_R3,4             0x00ff8080
CMD_SEND:1
                ARG                      0x40300000
                MMC_RSP_R3,4             0x00ff8080
CMD_SEND:1
                ARG                      0x40300000
                MMC_RSP_R3,4             0xc0ff8080
CMD_SEND:2
                ARG                      0x00000000
                RET                      -70
CMD_SEND:2
                ARG                      0x00000000
                RET                      -70
CMD_SEND:2
                ARG                      0x00000000
                RET                      -70
CMD_SEND:2
                ARG                      0x00000000
                RET                      -70
CMD_SEND:2
                ARG                      0x00000000
                RET                      -70
CMD_SEND:2
                ARG                      0x00000000
                RET                      -70
Command failed, result=1
U-Boot >

I believe the -70 error is an ECOM error  (Communication error on send).
However this does not occur when eMMC is in HS mode for example.
and even in DDR mode, before executing the "mmc dev 2" cmd, the
communication with the emmc with "load" works without a hitch.



Le lun. 26 juil. 2021 à 10:03, Jaehoon Chung <jh80.chung at samsung.com> a
écrit :

> Hi,
>
> On 7/26/21 4:41 PM, Abder wrote:
> > Hi,
> >
> > I have been trying recently to optimize the boot time on a customized
> board
> > based on the IMX6DP.
> >
> > For the time being, I succeeded in enabling the DDR (dual data rate) mode
> > for the emmc to speed up the data rate for read and write cycles in
> u-boot.
> >
> > By reading a file from the emmc using the "load" command (e.g. load mmc
> 2:1
> > 0x12000000 file), I can see that the data rate has doubled, confirming
> that
> > the DDR mode is enabled.
> >
> > However, the problem I have is that when I execute the u-boot command
> "mmc
> > dev 2" to switch the current device to the onboard eMMC, the command
> fails
> > with the output below : (with DEBUG enabled)
>
> If you can enable CONFIG_MMC_TRACE, then you can get more information
> relevant to MMC.
> Could you also share log after enabled MMC_TRACE?
>
> Best Regards,
> Jaehoon Chung
>
> >
> > U-Boot >mmc dev 2
> > blk_find_device: if_type=6, devnum=2: usdhc at 02198000.blk, 6, 2
> > ofnode_read_u32: vmmc-supply: 0x33 (51)
> > ofnode_read_u32: vqmmc-supply: 0x33 (51)
> > clock is disabled (0Hz)
> > fixed_regulator_set_enable: dev='3p3v', enable=1, delay=0, has_gpio=0
> > clock is enabled (400000Hz)
> > Command failed, result=1
> > U-Boot >
> >
> > and after this command, any attempt to interact with the emmc (e.g. fatls
> > mmc 2:1 ) ends with failure.
> >
> > To enable the DDR mode, all I did was define the macro
> > CONFIG_SYS_FSL_ESDHC_HAS_DDR_MODE in the header of my board.
> >
> > Any help is greatly appreciated !
> >
> > --
> >
> > Abder,
> >
>
>