RTC access problem after kernel compile...

mlattari
mlattari used Ask the Experts™
on
Hi!

After I compiled the 2.6.31.4 kernel I get the error

"Cannot access the hardware clock via any known method "

with 2.6.22... it worked all without errors

1) The mainboard is based on Nvidia Nforce 4
2) /dev/rtc exists...
3) hwclock causes the same error
4) I attach RTC relevant .config lines

Pls help :-)))))

hmmm.... something more:

hwclock: Open of /dev/rtc failed, errno 19: No such device.
No usable clock interface found.
Cannot access the hardware clock via any known method

and....

util-linux-2.13-pre7 (maybe a new version helps....)
CONFIG_HPET_EMULATE_RTC=y
CONFIG_PM_TRACE_RTC=y
CONFIG_RTC_LIB=y
CONFIG_RTC_CLASS=y
CONFIG_RTC_HCTOSYS=y
CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
CONFIG_RTC_DEBUG=y
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
CONFIG_RTC_INTF_DEV=y
CONFIG_RTC_INTF_DEV_UIE_EMUL=y
CONFIG_RTC_DRV_CMOS=y
CONFIG_RTC_HCTOSYS_DEVICE="rtc0"

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Author

Commented:
nobody knows? :-((
Duncan RoeSoftware Developer

Commented:
hwclock works for me and I have the below modules loaded
16:28:09# hwclock --systohc
16:28:46# lsmod|grep rtc
rtc_cmos               10092  0 
rtc_core               15640  1 rtc_cmos
rtc_lib                 2268  1 rtc_core

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Duncan RoeSoftware Developer

Commented:
But I am on a much more recent system than you:
19:40:06$ uname -a
Linux dimstar 2.6.29.2-2-smp #5 SMP Fri May 22 23:04:34 EST 2009 i686 AMD Athlon(tm) 64 X2 Dual Core Processor 6000+ AuthenticAMD GNU/Linux

Check what you have with "make xconfig" in the Liux source directory. "Real Time Clock" is a separate entry in the "Device Drivers" section - ensure it is being built as a module (dot in the box) or is built-in to the kernel (tick in the box)
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Duncan RoeSoftware Developer

Commented:
Running make xconfig in my old /usr/src/linux-2.6.22.9 directory, I see the RTC used to be a bit different. I had RTC class configured as a module, with only /sys/class/rtc/rtcN (sysfs), /proc/driver/rtc (procfs for rtc0) and /dev/rtcN (character devices) ticked below that. Make sure you have at least those
Software Developer
Commented:
See if you have a /dev/rtc0. If you do, try symlinking it to /dev/rtc and see if hwclock then works. Newer versions of udev will make that link for you by default (mine does) but you may have to configure your udev to make it

Author

Commented:
thanks! :-)

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