Hey Jean,
Am 12.04.2016 09:02, schrieb Jean Delvare:
Hi Thilo,
On lun., 2016-04-11 at 11:24 +0200, Thilo Cestonaro wrote:
> Whenever I load the i2c-i801 smbus controller module I get a resource
conflict with the ACPI:
> -----------------------
> ACPI Warning: SystemIO range 0x000000000000F040-0x000000000000F05F
> conflicts with OpRegion 0x000000000000F040-0x000000000000F04F
> (\_SB_.PCI0.SBUS.SMBI) (20150619/utaddress-254)
> -----------------------
>
As the resource conflict is about the IO resource, I overworked the
i2c-i801 module to use the MEM resource which is altough available.
This is IMHO the better alternative to using the
"acpi_enforce_resources=lax" boot parameter.
The patched module is working on my machine.
To be honest, I didn't know the 82801 SMBus controller supported memory
access. Does it actually work since the first supported controller
(82801AA)?
Good question! Perhaps I will implement an IO and MEM access depending
on the ACPI conflict prioizing the IO access.
But anyway, I can't see how using it solves any problem. I guess you
access the very same registers, just using a different method. If the
BIOS is actually using the SMBus controller, you have exactly the same
conflict as before, the only difference is that it is no longer
reported. This would be a regression, not an improvement.
You are absolutely right, it doesn't solve anything so it is just an
alternative to the boot parameter.
The advantage IMHO is, that you don't need to add the boot parameter and
that this change only affects the module itself,
instead of like the parameter the whole system.
I can still show the conflict by checking the MEM resource and the IO
resource, so the user will be informed about the problem but can use
it's smbus.
Currently if the conflict will be shown the probe returns an error.
Hmm, perhaps showing the conflict and not returning with an error is the
more easier way. Many use the boot parameter and haven't reported
problems with it,
so I think using it despite the conflict wouldn't do any harm.
Cheers,
Thilo
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