lkml.org 
[lkml]   [2004]   [Nov]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: RTC Chip and IRQ8 on 2.6.9
    On Sat, 13 Nov 2004, Randy.Dunlap wrote:

    > linux-os wrote:
    >>
    >> I must use the RTC and IRQ8 in a driver being ported from
    >> 2.4.20 to 2.6.9. When I attempt request_irq(8,...), it
    >> returns -EBUSY. I have disabled everything in .config
    >> that has "RTC" in it.
    >>
    >> The RTC interrupt is used to precisely time the sequencing
    >> of a precision A/D converter. It is mandatory that I use
    >> it because the precise interval is essential for its
    >> IIR filter that produces 20 bits of resolution from a
    >> 16 bit A/D.
    >>
    >> CPU0
    >> 0: 60563767 IO-APIC-edge timer
    >> 1: 57096 IO-APIC-edge i8042
    >> 8: 1 IO-APIC-edge rtc
    >> 9: 0 IO-APIC-level acpi
    >> 12: 66 IO-APIC-edge i8042
    >> 14: 112322 IO-APIC-edge ide0
    >> 16: 0 IO-APIC-level uhci_hcd, uhci_hcd
    >> 18: 640 IO-APIC-level libata, uhci_hcd, Analogic Corp DLB
    >> 19: 0 IO-APIC-level uhci_hcd
    >> 20: 4894484 IO-APIC-level eth0
    >> 21: 110543 IO-APIC-level aic7xxx
    >> 23: 0 IO-APIC-level ehci_hcd
    >> NMI: 0 LOC: 60565403 ERR: 0
    >> MIS: 0
    >>
    >> This stuff works fine in 2.4.22 and, in fact, I'm the guy
    >> that added the global rtc_lock so that this very driver
    >> could run without interfering with anybody. Now, some code,
    >> somewhere (not in a module), has allocated the interrupt
    >> and generated exactly 1 interrupt. The kernel won't let
    >> me use that interrupt!
    >>
    >> How do I undo this so I can use my hardware on my machine?
    >
    > I happen to be running a 2.6.9-rc1 kernel right now, with
    > an IO APIC (P4 UP), and no RTC support built into it,
    > and /proc/interrupts show IRQ 8 empty/unassigned:
    >
    > CPU0
    > 0: 777037582 IO-APIC-edge timer
    > 1: 185323 IO-APIC-edge i8042
    > 7: 0 IO-APIC-edge parport0
    > 9: 0 IO-APIC-level acpi
    > 12: 2838473 IO-APIC-edge i8042
    > 14: 1197859 IO-APIC-edge ide0
    > 15: 42 IO-APIC-edge ide1
    > 17: 49 IO-APIC-level aic7xxx, ohci_hcd
    > 19: 0 IO-APIC-level uhci_hcd
    > 21: 197 IO-APIC-level ohci1394, ohci_hcd, ohci_hcd, ohci_hcd,
    > ohci_hc
    > d, ohci_hcd
    > 22: 832350 IO-APIC-level ehci_hcd, eth0
    > 23: 16387 IO-APIC-level es1371, uhci_hcd
    > NMI: 0
    > LOC: 776994543
    > ERR: 0
    > MIS: 0
    >
    >
    > Perhaps your .config and a simple test case would help.

    Yep. The .config needed to set up RTC as a module so that
    I could unload it (seriously) in order to free it up.

    Otherwise the built-in RTC software grabbed IRQ8 even though
    it never used it.

    Cheers,
    Dick Johnson
    Penguin : Linux version 2.6.9 on an i686 machine (5537.79 BogoMips).
    Notice : All mail here is now cached for review by John Ashcroft.
    98.36% of all statistics are fiction.
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 14:08    [W:0.025 / U:0.736 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site