topic i.MX6 SysRq : Emergency Remount R/O in i.MX Processors

i.MX6 SysRq : Emergency Remount R/O

micschrag — Mon, 13 Jul 2015 15:58:22 GMT

Good Morning,

I am working with the Freescale i.MX6 Dual Light SD processor, and have been having issues with the boot process. I have solved issues with removed components by modifying the kernel of our Android KitKat 4.4.2 OS. I have had to remove the following drivers: PCIe, V4L (removed to alleviate error messages), MAX11801, and Watchdog. The issue I am running into is that the boot seems to process correctly until the final few lines, where an emergency remount occurs and the CPUs shut down after about 8s. Furthermore, when I use it on a prototype board provided by Freescale, the boot processes perfectly fine. Here is the final lines of the boot process:

mma enable setting active
eth0: Freescale FEC PHY driver [Generic PHY] (mii_bus:phy_addr=1:01, irq=-1)
ADDRCONF(NETDEV_UP): eth0: link is not ready
acc_open
acc_release
ehci_fsl_bus_resume begins, Host 1
ehci_fsl_bus_resume ends, Host 1
ehci_fsl_bus_resume begins, DR
mtp_open
init: sys_prop: permission denied uid:1003 name:service.bootanim.exit
ehci_fsl_bus_suspend begins, Host 1
ehci_fsl_bus_suspend ends, Host 1
SysRq : Emergency Remount R/O
EXT4-fs (mmcblk0p4): re-mounted. Opts: (null)
EXT4-fs (mmcblk0p6): re-mounted. Opts: (null)
Emergency Remount complete
imx2-wdt imx2-wdt.0: Device shutdown: Expect reboot!
Disabling non-boot CPUs ...

I have seen some suggestions that this may be due to the Watchdog Timer, but that has been disabled so that should not be the problem. Does anyone have any ideas on what could be causing my errors?

Thanks for your help.

Re: i.MX6 SysRq : Emergency Remount R/O

igorpadykov — Fri, 17 Jul 2015 04:24:38 GMT

Hi Michael

Device may be shutdown by internal kernel timer, not only watchdog.

This may be caused that system automatically decides to remount a mmc read-only,

that either means that: the mmc or its filesystem is broken.

In general one can debug "drivers/tty/sysrq.c" to print current task(to know who is doing.

Best regards

igor

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Re: i.MX6 SysRq : Emergency Remount R/O

zhanghuan — Wed, 30 Mar 2016 07:42:55 GMT

HI, I have met the same problem. Have you solved it? can you give me some ideas?

Thanks very much

Re: i.MX6 SysRq : Emergency Remount R/O

zhanghuan — Wed, 30 Mar 2016 07:45:38 GMT

Oh, I forgot say it. I have only remove the max11801 driver, and setup a few gpios. I have no ideas about it……