I/O address 0x0cd6 already in use

I/O address 0x0cd6 already in use

[Ioan Moldovan]

At every boot of my PC I noticed the following error telling me the IO
address 0x0cd6 is already in use:

[    6.083233] sp5100_tco: SP5100/SB800 TCO WatchDog Timer Driver v0.05
[    6.083292] sp5100_tco: PCI Vendor ID: 0x1022, Device ID: 0x780b,
Revision ID: 0x16
[    6.083296] sp5100_tco: I/O address 0x0cd6 already in use

Not being a kernel developer, I have no way to fix this.

CPU Details:
vendor_id    : AuthenticAMD
cpu family    : 21
model        : 48
model name    : AMD Athlon(tm) X4 860K Quad Core Processor
stepping    : 1
microcode    : 0x6003104

Re: I/O address 0x0cd6 already in use

[Guenter Roeck]

On 07/07/2016 06:12 AM, Ioan Moldovan wrote:
> At every boot of my PC I noticed the following error telling me the IO
> address 0x0cd6 is already in use:
>
> [    6.083233] sp5100_tco: SP5100/SB800 TCO WatchDog Timer Driver v0.05
> [    6.083292] sp5100_tco: PCI Vendor ID: 0x1022, Device ID: 0x780b,
> Revision ID: 0x16
> [    6.083296] sp5100_tco: I/O address 0x0cd6 already in use
>
> Not being a kernel developer, I have no way to fix this.
>

You probably won't be able to fix it. Try "sudo cat /proc/ioports";
it might tell you who is using that io address space.

Guenter

> CPU Details:
> vendor_id    : AuthenticAMD
> cpu family    : 21
> model        : 48
> model name    : AMD Athlon(tm) X4 860K Quad Core Processor
> stepping    : 1
> microcode    : 0x6003104
> --
> To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: I/O address 0x0cd6 already in use

[Guenter Roeck]

On Thu, Jul 07, 2016 at 08:19:56PM +0300, Ioan Moldovan wrote:
> [ioan@ioanpc ~]$ sudo cat /proc/ioports | grep 0cd6
>   0cd6-0cd7 : pnp 00:07
>     0cd6-0cd7 : smba_idx
> 
> Look like pnp & smba_idx, no idea what those 2 are!
> 

Please don't drop the mailing list from your replies; others may be interested
in the problem as well. Also, please avoid top-posting.

The culprit is drivers/i2c/busses/i2c-piix4.c, which specifically requests
IO address 0xcd6-0cd7. In earlier kernels, that driver released the region
after it was done with its initialization. This is no longer the case;
instead, the region is only released when the driver is unloaded.

In other words, it is now either-or. You can load the watchdog driver
or the i2c driver, but not both. 

This was introduced with commit 2fee61d22e60 ("i2c: piix4: Add support
for multiplexed main adapter in SB800"). Copying the author and the i2c
mailing list for comments.

Guenter

> 2016-07-07 18:14 GMT+03:00 Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>:
> > On 07/07/2016 06:12 AM, Ioan Moldovan wrote:
> >>
> >> At every boot of my PC I noticed the following error telling me the IO
> >> address 0x0cd6 is already in use:
> >>
> >> [    6.083233] sp5100_tco: SP5100/SB800 TCO WatchDog Timer Driver v0.05
> >> [    6.083292] sp5100_tco: PCI Vendor ID: 0x1022, Device ID: 0x780b,
> >> Revision ID: 0x16
> >> [    6.083296] sp5100_tco: I/O address 0x0cd6 already in use
> >>
> >> Not being a kernel developer, I have no way to fix this.
> >>
> >
> > You probably won't be able to fix it. Try "sudo cat /proc/ioports";
> > it might tell you who is using that io address space.
> >
> > Guenter
> >
> >> CPU Details:
> >> vendor_id    : AuthenticAMD
> >> cpu family    : 21
> >> model        : 48
> >> model name    : AMD Athlon(tm) X4 860K Quad Core Processor
> >> stepping    : 1
> >> microcode    : 0x6003104
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-watchdog"
> >> in
> >> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>
> >
> 
> 
> 
> -- 
> Ioan Moldovan
> ioan.moldovan1999-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
--
To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
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More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: I/O address 0x0cd6 already in use

[Guenter Roeck]

On Thu, Jul 07, 2016 at 08:19:56PM +0300, Ioan Moldovan wrote:
> [ioan@ioanpc ~]$ sudo cat /proc/ioports | grep 0cd6
>   0cd6-0cd7 : pnp 00:07
>     0cd6-0cd7 : smba_idx
> 
> Look like pnp & smba_idx, no idea what those 2 are!
> 

Please don't drop the mailing list from your replies; others may be interested
in the problem as well. Also, please avoid top-posting.

The culprit is drivers/i2c/busses/i2c-piix4.c, which specifically requests
IO address 0xcd6-0cd7. In earlier kernels, that driver released the region
after it was done with its initialization. This is no longer the case;
instead, the region is only released when the driver is unloaded.

In other words, it is now either-or. You can load the watchdog driver
or the i2c driver, but not both. 

This was introduced with commit 2fee61d22e60 ("i2c: piix4: Add support
for multiplexed main adapter in SB800"). Copying the author and the i2c
mailing list for comments.

Guenter

> 2016-07-07 18:14 GMT+03:00 Guenter Roeck <linux@roeck-us.net>:
> > On 07/07/2016 06:12 AM, Ioan Moldovan wrote:
> >>
> >> At every boot of my PC I noticed the following error telling me the IO
> >> address 0x0cd6 is already in use:
> >>
> >> [    6.083233] sp5100_tco: SP5100/SB800 TCO WatchDog Timer Driver v0.05
> >> [    6.083292] sp5100_tco: PCI Vendor ID: 0x1022, Device ID: 0x780b,
> >> Revision ID: 0x16
> >> [    6.083296] sp5100_tco: I/O address 0x0cd6 already in use
> >>
> >> Not being a kernel developer, I have no way to fix this.
> >>
> >
> > You probably won't be able to fix it. Try "sudo cat /proc/ioports";
> > it might tell you who is using that io address space.
> >
> > Guenter
> >
> >> CPU Details:
> >> vendor_id    : AuthenticAMD
> >> cpu family    : 21
> >> model        : 48
> >> model name    : AMD Athlon(tm) X4 860K Quad Core Processor
> >> stepping    : 1
> >> microcode    : 0x6003104
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-watchdog"
> >> in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>
> >
> 
> 
> 
> -- 
> Ioan Moldovan
> ioan.moldovan1999@gmail.com

Re: I/O address 0x0cd6 already in use

[Ioan Moldovan]

Okay, but won't unloading i2c cause errors?
Or won't unloading watchdog and keeping just i2c also cause errors?

(And sorry for top-posting, it's the first time I use a mailing list)

Re: I/O address 0x0cd6 already in use

[Guenter Roeck]

On 07/07/2016 09:59 PM, Ioan Moldovan wrote:
> Okay, but won't unloading i2c cause errors?

Not loading the i2c controller would mean that you can not access
any of the i2c devices connected to the i2c bus.

> Or won't unloading watchdog and keeping just i2c also cause errors?

Unloading (or, rather, not loading) the watchdog driver means that
you won't be able to use the watchdog.

Sure, both is undesirable, but unless we hear otherwise we have to assume
that the change to the i2c driver was made on purpose, and there isn't
really anything we can do about it.

Guenter

Re: I/O address 0x0cd6 already in use

[Ioan Moldovan]

Okay, thanks for all the help!

Re: I/O address 0x0cd6 already in use

[Guenter Roeck]

On 07/08/2016 09:08 PM, Ioan Moldovan wrote:
> Okay, thanks for all the help!

I wouldn't call that help :-(. It is broken, but I don't see an easy way to fix it.

Guenter

Re: I/O address 0x0cd6 already in use

[Ioan Moldovan]

How about reporting this to i2c, and asking the devs there if they
need that I/O Addr.
Maybe this can be patched in 4.6.4 :)

Re: I/O address 0x0cd6 already in use

[Guenter Roeck]

On 07/09/2016 06:34 AM, Ioan Moldovan wrote:
> How about reporting this to i2c, and asking the devs there if they
> need that I/O Addr.

I _did_ cc the i2c mailing list in my first reply. Remember, I asked you not to drop
the mailing lists in your replies ?

Guenter