TDA4VM: Restart the TDA4 from A72 Linux with reboot command.

Tiebing Guo

Part Number: TDA4VM
Other Parts Discussed in Thread: CSD

Dear TIs'

We just setup a new project which use TDA4VM Soc and boot from emmc with SPL bootloader，the SW is base on TI-SDK 0703 release.

while testing the system restart funcion from the A72 Linux side: input "systemctl reboot" or just run "reboot" in the tty console.

On some HW it works, but some not ! it can't restart, the system just hung up after all systemd services stop and invoke kernel restart.

After a long term corss-testing, finally, we found the KEY is a special cmd in uboot console when flashing emmc:

Then the reboot cmd works on!

As I know the mmc rst-function 0 1 usage is:

* Modify EXT_CSD[162] which is RST_n_FUNCTION based on the given value
* for enable. Note that this is a write-once field for non-zero values.

I'd like to know why don't enable the emmc HW rst-function will block the TDA4 hw reboot?

Best regards

Tiebing.

over 4 years ago

0 Keerthy J over 4 years ago

TI__Guru**** 170160 points

Hi,

Have you tried the below commands already:

=> mmc partconf 0 1 1 1
=> mmc bootbus 0 2 0 0

To give the ROM access to the boot partition, the above commands must be used for the first time:

Link: https://software-dl.ti.com/jacinto7/esd/processor-sdk-linux-jacinto7/08_01_00_07/exports/docs/linux/Foundational_Components/U-Boot/UG-Memory.html

The above link has comprehensive details about eMMC boot mode.

Let me know if that helps.

Best Regards,
Keerthy

0 Tiebing Guo over 4 years ago in reply to Keerthy J

Prodigy 40 points

Hi Keerthy

Yes, we already set these mmc boot parameters. The target board can boot up well from emmc, but the system CAN NOT REBOOT with A72 linux reboot cmd! but if we run this cmd in uboot cmdline, the Linux reboot cmd is always working

=> mmc rst-function 0 1

that's why I ask this question.

+1 Keerthy J over 4 years ago in reply to Tiebing Guo

TI__Guru**** 170160 points

Hi,

I believe the eMMC part on your custom board needs that. Here is a patch that explains that: https://lists.denx.de/pipermail/u-boot/2014-February/173017.html

Quoting the commit log:

Some eMMC chips may need the RST_n_FUNCTION bit set to a non-zero value
in order for warm reset of the system to work.  Details on this being
required will be part of the eMMC datasheet.  Also add using this
command to the dra7xx README.


I believe that is the reason why "mmc  rst-function 0  1" helps on your board.

If no further questions please click on verify answer.

- Keerthy

0 Tiebing Guo over 4 years ago in reply to Keerthy J

Prodigy 40 points

Great，this is helpful answer for me!

Thank you so much~

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TDA4VM: Restart the TDA4 from A72 Linux with reboot command.