Hi, In continuation to my earlier email, here are the kernel logs [last_kmsg on watchdog reboot] http://paste.ubuntu.com/12319445/ http://paste.ubuntu.com/12319449/ http://paste.ubuntu.com/12319453/ http://paste.ubuntu.com/12319460/ One thought we had was that may be sudden time-stamp jump is causing the crash. So, we built kernel with CONFIG_NO_HZ. But that didn't help. We have also tried kernel image built with CONFIG_PRINTK_TIME & CONFIG_HAVE_UNSTABLE_SCHED_CLOCK and options. Still we run in to identical problems. We have total three product variants using similar platform. The problem occurs only on one of the three products. Also, on the failing product, some devices are stable [have never failed the tests]. Out of failing boards, some boards have higher failure frequency. Could the problem be related to Power/Clock management? Is there any particular item we can check w.r.t. hardware. Regards, Kunal On 9 September 2015 at 13:50, Kunal Singh <kunal.singh@xxxxxxxxxxxxxxxxx> wrote: > Hi, > > We have a OMAP4460 based platform running Android Jellybean. We have > observed that OMAP can totally freeze at times, leading to watchdog > reboot. > > There are two test cases which consistently reproduce the problem > - Running Camera Preview > - copying large files to eMMC. > > Both of the above test cases involve heavy DMA. So, we are suspecting > that crash may be related to some DMA processing/logic. > > After the watchdog reboot, last_kmsg consistently show two things > - A sudden jump in timestamps prior to crash > - Unhandled Fault in the kernel logs. The fault type can vary, but > it's mostly one of the following > - Unhandled fault: imprecise external abort (0x1406) > - Unhandled fault: external abort on non-linefetch (0x1008) > > From last_kmsg, the PC/LR is mostly at omap4_prm_inst_read_inst_reg > and omap4_pwrdm_read_pwrst respectively. Sometimes at other places > (e.g. sched_clock ) > > Can someone suggest what might be causing this? > > Regards, > Kunal -- Kunal Singh Embedded Systems Developer, BARTEC PIXAVI Email:kunal.singh@xxxxxxxxxxxxxxxxx Mobile:+91 9818408590 Skype:kunalbangalore Website:www.bartec-pixavi.com Confidentiality: The contents of this email including all text and attachments are hereby marked as confidential and proprietary information of BARTEC PIXAVI -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
