3.12 on AM335X -- reboot problem

Eric Lee4

I am working on Linux 3.12 of AM335x custom board.

When I reboot using "# shutdown now -r" command, it will stop at uboot:

U-Boot SPL 2014.04-00513-gdda0dbf-dirty (Apr 23 2014 - 17:10:13)

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I did not have this problem in v3.2 kernel. It seems that the i2c0 goes wrong so that it cannot read EEPROM. If I power off and on, it boots well. Could you confirm this problem?

-Eric

over 11 years ago

0 Miroslav Kiradzhiyski XID over 11 years ago

TI__Mastermind 25235 points

Eric,

Where are you booting from?

I just checked and when booting from SD card, everything is working correctly.

Best regards,
Miroslav

0 Eric Lee4 over 11 years ago

Expert 1285 points

One more findings.

If I keep entering "# i2cdetect -y -r 0" this command very quickly about 60 times. The i2c0 crash and the system reboot and it hang on uboot first line like my previous post.

-Eric

0 Eric Lee4 over 11 years ago in reply to Eric Lee4

Expert 1285 points

I am booting from SD card.

-Eric

0 Eric Lee4 over 11 years ago in reply to Eric Lee4

Expert 1285 points

Miroslav,

Did you test under v3.12?

-Eric

0 Miroslav Kiradzhiyski XID over 11 years ago in reply to Eric Lee4

TI__Mastermind 25235 points

Eric Lee4 said:
Did you test under v3.12?

Yes, I test using SDK 07.00.00.00.

Do you have the CONFIG_SPL_OS_BOOT option enabled in SPL/U-Boot ? If yes, can you try holding the 'c' button while rebooting and entering the SPL ?

Please put some prints inside the spl_mmc_load_image() function inside <u-boot_dir>/common/spl/spl_mmc.c or enable the debug messages that are already inside?

To enable the debug messages just do:

#define DEBUG

Best regards,
Miroslav

0 Eric Lee4 over 11 years ago in reply to Miroslav Kiradzhiyski XID

Expert 1285 points

Miroslav,

I will add some more debug messages to figure out and will get you back later.

-Eric

0 John Murphy1 over 11 years ago in reply to Eric Lee4

Expert 1210 points

Sounds like it could be an I2C Bus Busy (BB) condition. You could check the SDA and SCL lines, they should be idle high during the reboot (or restart of u-boot).

To recover from this, you could try sending out say 100 clocks cycles on SCL before attempting I2C comms.

0 Eric Lee4 over 11 years ago in reply to John Murphy1

Expert 1285 points

John,

You are correct and your solution works.

-Eric

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3.12 on AM335X -- reboot problem