Jetson TK1 reports "Timed out wiating for pll_m lock bit ([0x90] = 0x44004d01)"

Hi guys,

I'm using Jetson TK1 board with original Tegra software package.
The kernel frequently reports the message that:
[    643.916659]  Timed out wiating for pll_m lock bit ([0x90] = 0x44004d01)
[    644.264920]  Timed out wiating for pll_m lock bit ([0x90] = 0x44004d01)
[    644.665915]  Timed out wiating for pll_m lock bit ([0x90] = 0x44004d01)
[    644.967634]  Timed out wiating for pll_m lock bit ([0x90] = 0x44004d01)

It seems that this issue doesn't harm the system yet.
I'm not sure whether 0x44004d01 is a virtual address or a physical address. I look the address up in Tk1's spec. However, it shows that 0x44004d01 is unused in Physical address space.
The Tegra Linux Driver Package version in use is 21.1.0_armhf.

Could you please have a look at this issue?

Thank you.

Best regards,
David

May I know what is being run, when this spew was hit? We take every care to not get/leave_behind any kind of thwarting spew. Pls provide the steps followed to repro this.