svn commit: r360241 - head/sys/dev/ichiic

[Andriy Gapon]

On 24/04/2020 17:29, Warner Losh wrote:
> 
> 
> On Fri, Apr 24, 2020 at 1:49 AM Andriy Gapon <avg at freebsd.org
> <mailto:avg at freebsd.org>> wrote:
> 
>     Author: avg
>     Date: Fri Apr 24 07:49:21 2020
>     New Revision: 360241
>     URL: https://svnweb.freebsd.org/changeset/base/360241
> 
>     Log:
>       ig4: ensure that drivers always attach in correct order
> 
>       Use DRIVER_MODULE_ORDERED(SI_ORDER_ANY) so that ig4's ACPI attachment
>       happens after iicbus and acpi_iicbus drivers are registered.
> 
>       I have seen a problem where iicbus attached under ig4 instead of
>       acpi_iicbus when ig4.ko was loaded with kldload.  I believe that that
>       happened because ig4 driver was a first driver to register, it attached
>       and created an iicbus child.  Then iicbus driver was registered and,
>       since it was the only driver that could attach to the iicbus child
>       device, it did exactly that.  After that acpi_iicbus driver was
>       registered.  It would be able to attach to the iicbus device, but it was
>       already attached, so nothing happened.
> 
> 
> Can you post more details of which devices are affected? From the description
> and the patch, I don't see how this could fix things.

I think I listed them all: ig4iic with acpi attachment, iicbus and acpi_iicbus.
acpi
 \--- ig4iic
       \---- iicbus vs acpi_iicbus

I tried to explain the problem and the fix in the commit message.  If you want
to discuss any specifics, let's continue with specifics.  If there is anything
unclear in my explanation, I can clarify, but I need to understand what needs to
be clarified.


>       MFC after:    2 weeks
> 
>     Modified:
>       head/sys/dev/ichiic/ig4_acpi.c
> 
>     Modified: head/sys/dev/ichiic/ig4_acpi.c
>     ==============================================================================
>     --- head/sys/dev/ichiic/ig4_acpi.c      Fri Apr 24 05:05:58 2020       
>     (r360240)
>     +++ head/sys/dev/ichiic/ig4_acpi.c      Fri Apr 24 07:49:21 2020       
>     (r360241)
>     @@ -192,5 +192,6 @@ static driver_t ig4iic_acpi_driver = {
>             sizeof(struct ig4iic_softc),
>      };
> 
>     -DRIVER_MODULE(ig4iic, acpi, ig4iic_acpi_driver, ig4iic_devclass, 0, 0);
>     +DRIVER_MODULE_ORDERED(ig4iic, acpi, ig4iic_acpi_driver, ig4iic_devclass, 0, 0,
>     +    SI_ORDER_ANY);
>      MODULE_DEPEND(ig4iic, acpi, 1, 1, 1);
> 


-- 
Andriy Gapon