Linux/am3352: System time looping

Kyle von Schmacht

Part Number: AM3352
Other Parts Discussed in Thread: TPS65217

Tool/software: Linux

To whom it may concern,

We're using a custom board based on the BeagleBone Black, and are experiencing a "System time loop" similar to those in these threads:

https://e2e.ti.com/support/arm/sitara_arm/f/791/p/506562/1837427

e2e.ti.com/.../237808

Proc: AM3352B ZCZ A100

Clocks: 24MHz, 32.762kHz crystals are installed, OSC[1:0] grounds are tied to board ground (advisory 1.0.30)

Maxim i2c RTC chip used to for linux RTC function

Power: TPS65217 replaced with TP65910

The issue appears after several hours to several days of continuous operation.

We've been using this board design for almost a year without this issue appearing,

So far we've detected the issue in our most recent run (date/lot code 63ARZCW) although it may exist on older runs as well.

Are there any known fixes?

Thanks for your help,

Kyle

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

What Linux version is this?

0 Kyle von Schmacht over 8 years ago in reply to Biser Gatchev-XID

Prodigy 120 points

Biser,

We're using a Yocto based linux (Poky-Krogoth) adapted from the beaglebone black's.

We forked about a year ago.

Thanks for your help,

Kyle

0 Biser Gatchev-XID over 8 years ago in reply to Kyle von Schmacht

TI__Guru**** 393215 points

Can you try changing the system time source clock to be taken from the main oscillator, as suggested here: e2e.ti.com/.../417299

0 Kyle von Schmacht over 8 years ago in reply to Biser Gatchev-XID

Prodigy 120 points

Biser,

Units are using the 24 Mhz main oscillator for clocking.

Checking the source code indicates that the errata changes suggested here [ https://e2e.ti.com/support/arm/sitara_arm/f/791/t/270632

has already been applied.

Thanks,

Kyle

0 Biser Gatchev-XID over 8 years ago in reply to Kyle von Schmacht

TI__Guru**** 393215 points

To narrow down the root cause, could you check if this happens with the latest SDK: software-dl.ti.com/.../index_FDS.html

0 Kyle von Schmacht over 8 years ago in reply to Biser Gatchev-XID

Prodigy 120 points

Biser,

Included the linux rev you suggested in our yocto build, we're starting tests now.

I'll report back with the results.

thanks,

Kyle

0 Kyle von Schmacht over 8 years ago in reply to Kyle von Schmacht

Prodigy 120 points

Biser,

We've had the updated code running on several units, and so far so good.

We'll give it several more days to be absolutely sure.

In the meantime, to help our understanding, do you or your coworkers know of any changes made to the SDK that might be relevant to the issue?

[i.e. timer and clock code, platform specific modifications]

Thanks for your help,

Kyle

0 Biser Gatchev-XID over 8 years ago in reply to Kyle von Schmacht

TI__Guru**** 393215 points

I don't know which kernel you were using originally. Current SDK is kernel v4.4.41.

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Linux/am3352: System time looping