* RTC Chip and IRQ8 on 2.6.9
@ 2004-11-12 16:47 linux-os
2004-11-14 4:36 ` Randy.Dunlap
2004-11-14 12:27 ` Florian Schmidt
0 siblings, 2 replies; 5+ messages in thread
From: linux-os @ 2004-11-12 16:47 UTC (permalink / raw)
To: Linux kernel
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?
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.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: RTC Chip and IRQ8 on 2.6.9
2004-11-12 16:47 RTC Chip and IRQ8 on 2.6.9 linux-os
@ 2004-11-14 4:36 ` Randy.Dunlap
2004-11-14 14:25 ` linux-os
2004-11-14 12:27 ` Florian Schmidt
1 sibling, 1 reply; 5+ messages in thread
From: Randy.Dunlap @ 2004-11-14 4:36 UTC (permalink / raw)
To: linux-os; +Cc: Linux kernel
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.
--
~Randy
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: RTC Chip and IRQ8 on 2.6.9
2004-11-12 16:47 RTC Chip and IRQ8 on 2.6.9 linux-os
2004-11-14 4:36 ` Randy.Dunlap
@ 2004-11-14 12:27 ` Florian Schmidt
2004-11-14 14:28 ` linux-os
1 sibling, 1 reply; 5+ messages in thread
From: Florian Schmidt @ 2004-11-14 12:27 UTC (permalink / raw)
To: linux-os; +Cc: linux-os, Linux kernel
On Fri, 12 Nov 2004 11:47:10 -0500 (EST)
linux-os <linux-os@chaos.analogic.com> 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.
>
> 8: 1 IO-APIC-edge rtc
maybe it's the HPET timer providing rtc emulation?
flo
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: RTC Chip and IRQ8 on 2.6.9
2004-11-14 4:36 ` Randy.Dunlap
@ 2004-11-14 14:25 ` linux-os
0 siblings, 0 replies; 5+ messages in thread
From: linux-os @ 2004-11-14 14:25 UTC (permalink / raw)
To: Randy.Dunlap; +Cc: Linux kernel
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.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: RTC Chip and IRQ8 on 2.6.9
2004-11-14 12:27 ` Florian Schmidt
@ 2004-11-14 14:28 ` linux-os
0 siblings, 0 replies; 5+ messages in thread
From: linux-os @ 2004-11-14 14:28 UTC (permalink / raw)
To: Florian Schmidt; +Cc: Linux kernel
On Sun, 14 Nov 2004, Florian Schmidt wrote:
> On Fri, 12 Nov 2004 11:47:10 -0500 (EST)
> linux-os <linux-os@chaos.analogic.com> 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.
>>
>> 8: 1 IO-APIC-edge rtc
>
> maybe it's the HPET timer providing rtc emulation?
>
> flo
>
It turned out to be RTC timer software that, when built-in,
grabbed IRQ8 even though it didn't use it. I reconfigured
it as a module. Then, when I unload the module, the IRQ gets
freed up. (Fedora loads, I guess, everything...).
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.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2004-11-12 16:47 RTC Chip and IRQ8 on 2.6.9 linux-os
2004-11-14 4:36 ` Randy.Dunlap
2004-11-14 14:25 ` linux-os
2004-11-14 12:27 ` Florian Schmidt
2004-11-14 14:28 ` linux-os
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