求教关于am335x linux系统时间乱跳

这个问题这两天经常遇到，http://www.deyisupport.com/question_answer/dsp_arm/sitara_arm/f/25/t/122428.aspx

这个是你的同事吗？

建议是一样的，建议你们先检查一下硬件设计，在AM335x的errata上面已经提到过这种因为噪声问题而引入的时间错误情况。

Advisory 1.0.30 OSC0 and OSC1: Noise Immunity Improved When Crystal Circuit is Connected
Directly to PCB Digital Ground
Revisions Affected 2.1, 2.0, 1.0
Details The Sitara AM335x ARM Cortex-A8 Microprocessors (MPUs) data manual (literature
number SPRS717), revision F and earlier, has specified OSC0 crystal circuit grounds
only be connected to VSS_OSC in both ZCE and ZCZ packages, and OSC1 crystal
circuit grounds only be connected to VSS_RTC in the ZCZ package. The VSS_OSC and
VSS_RTC terminals are connected to the VSS terminals inside the AM335x device,
which connects the crystal circuit to the PCB digital ground, but this ground connection is
a higher impedance connection than a direct connection to the PCB digital ground.
The higher impedance connection through the AM335x device to the PCB digital ground
makes it easier for electrical noise to couple into the crystal circuit. If the noise is large
enough, it is possible that the oscillator output may produce clock glitches to various
internal logic circuits. These clock glitches may cause unexpected behavior.
Workarounds Connect the VSS_OSC and VSS_RTC terminals and respective crystal circuit
component grounds directly to the nearest PCB digital ground, making it more difficult for
noise to couple into the crystal circuit.