/dev/rtc cannot be read

[Lincoln Stein]

Binary package hint: linux-image-2.6.20-16-generic

I'm using Ubuntu 7.04 on an amd64 platform. At some point after an automatic kernel upgrade the real time clock stopped working. Here is what cat /dev/rtc shows:

     cat: /dev/rtc: Device or resource busy

Here is what hwclock gives me:

    hwclock --debug
    hwclock from util-linux-2.12r
   hwclock: Open of /dev/rtc failed, errno=16: Device or resource busy.
   No usable clock interface found.
   Cannot access the Hardware Clock via any known method.

I've booted with the Ubuntu 6.10 "live" disk (amd64) and confirmed that the RTC is available. I've also booted with a vanilla 2.6.22 kernel and found that RTC works there too. I'm pretty sure that the original generic kernel that came with 7.04 was working, but sadly I'm not aware of which kernel update broke it.

lspci is attached:

00:00.0 Host bridge: VIA Technologies, Inc. K8M890CE Host Bridge
00:00.1 Host bridge: VIA Technologies, Inc. K8M890CE Host Bridge
00:00.2 Host bridge: VIA Technologies, Inc. K8M890CE Host Bridge
00:00.3 Host bridge: VIA Technologies, Inc. K8M890CE Host Bridge
00:00.4 Host bridge: VIA Technologies, Inc. K8M890CE Host Bridge
00:00.5 PIC: VIA Technologies, Inc. K8M890CE I/O APIC Interrupt Controller
00:00.7 Host bridge: VIA Technologies, Inc. K8M890CE Host Bridge
00:01.0 PCI bridge: VIA Technologies, Inc. VT8237 PCI bridge [K8T800/K8T890 South]
00:02.0 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller
00:03.0 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller
00:0a.0 FireWire (IEEE 1394): VIA Technologies, Inc. IEEE 1394 Host Controller (rev 80)
00:0b.0 Ethernet controller: Atheros Communications, Inc. AR5212 802.11abg NIC (rev 01)
00:0f.0 IDE interface: VIA Technologies, Inc. VIA VT6420 SATA RAID Controller (rev 80)
00:0f.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
00:10.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.4 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 86)
00:11.0 ISA bridge: VIA Technologies, Inc. VT8237 ISA bridge [KT600/K8T800/K8T890 South]
00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 60)
00:12.0 Ethernet controller: VIA Technologies, Inc. VT6102 [Rhine-II] (rev 78)
00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
02:00.0 VGA compatible controller: nVidia Corporation GeForce 7300 GS (rev a1)

[Lincoln Stein (lstein)]

Followup -- the problem I'm experiencing has nothing to do with the kernel. It has to do with Timidity opening the snd_rtctimer module. Now I just need to figure out how to run timidity without disabling /dev/rtc.

[Launchpad Janitor (janitor)]

Beginning with the Hardy Heron 8.04 development cycle, all open Ubuntu kernel bugs need to be reported against the "linux" kernel package. We are automatically migrating this bug to the new "linux" package. However, development has already began for the upcoming Intrepid Ibex 8.10 release. It would be helpful if you could test the upcoming release and verify if this is still an issue - http://www.ubuntu.com/testing . If the issue still exists, please update this report by changing the Status of the "linux" task from "Incomplete" to "New". We appreciate your patience and understanding as we make this transition. Thanks!