Re: puc fails to attach serial ports

On Tue, 2005-12-13 at 13:38 +0000, Gavin Atkinson wrote:
> On Mon, 2005-12-12 at 17:04 +0300, Gleb Smirnoff wrote:
> > On Sun, Dec 11, 2005 at 06:22:40PM +0000, Gavin Atkinson wrote:
> > G> I'm trying to use puc(4) under RELENG_6 to attach the two serial ports on 
> > G> a PCI card I have, but it's not working.  It also fails under 6.0-RELEASE, 
> > G> I don't have the ability to test earlier versions.
> > G> 
> > G> How can I further diagnose why this card is not getting recognised?
> > 
> > Afaik, you need 'device uart', that will attach to your pucs.
> 
> No, as far as I can tell, it's sio that should be attaching.  I've
> loaded the uart module anyway and it still fails.
> 
> With BUS_DEBUG defined, I see the following:
> 
> devclass_find_internal:761: looking for puc
> devclass_add_device:1356: (null) in devclass puc
> devclass_alloc_unit:1289: unit -1 in devclass puc
> devclass_alloc_unit:1329: now: unit 0 in devclass puc
> puc0: <Dolphin Peripherals 4036> port 0x18c0-0x18df irq 25 at device 9.0
> on pci0
> puc0: Reserved 0x20 bytes for rid 0x10 type 4 at 0x18c0
> port rid 16 bst 0, start 18c0, end 18df
> puc0: i 0, type sio, ressz 8, type 1
> devclass_find_internal:761: looking for sio
> puc: Using sio2
> device_add_child_ordered:1542: sio at puc with order 0 as unit 2
> make_device:1427: sio at puc as unit 2
> devclass_find_internal:761: looking for sio
> devclass_add_device:1356: (null) in devclass sio
> devclass_alloc_unit:1289: unit 2 in devclass sio
> devclass_alloc_unit:1329: now: unit 2 in devclass sio
> puc: type 1, bar 10, offset 0
> devclass_find_driver_internal:1019: sio in devclass puc
> devclass_find_driver_internal:1026: not found
> puc0: i 1, type sio, ressz 8, type 1
> devclass_find_internal:761: looking for sio
> puc: Using sio3
> device_add_child_ordered:1542: sio at puc with order 0 as unit 3
> make_device:1427: sio at puc as unit 3
> devclass_find_internal:761: looking for sio
> devclass_add_device:1356: (null) in devclass sio
> devclass_alloc_unit:1289: unit 3 in devclass sio
> devclass_alloc_unit:1329: now: unit 3 in devclass sio
> puc: type 1, bar 10, offset 8
> devclass_find_driver_internal:1019: sio in devclass puc
> devclass_find_driver_internal:1026: not found
> 
> I'm sure somebody with more newbus knowledge will know exactly what that
> means...  Are we somehow missing a devclass_add_driver(9) call from the
> puc initialisation?  I'm almost at the point now where I can't
> understand how it could possibly be working for anyone else.

OK, I've cracked what's happening.  Indeed we are somehow missing a call
to devclass_add_driver(9).  I was loading puc as a module, and in that
case the following relevant calls to devclass_add_driver are made:

devclass_add_driver: adding puc to cardbus
devclass_add_driver: adding puc to pci
devclass_add_driver: adding puc to pccard
devclass_add_driver: adding uart to puc
devclass_add_driver: adding sio to pccard
devclass_add_driver: adding sio to pci
devclass_add_driver: adding sio to cardbus
devclass_add_driver: adding sio to isa
devclass_add_driver: adding sio to acpi

When compiling puc into the kernel as opposed to using the module, the
following extra call is made:

devclass_add_driver: adding sio to puc

I don't understand why the DRIVER_METHOD(sio, puc, ...) is being ignored
in the puc-as-a-module case.  Is this expected behaviour?  I'm guessing
it's not.  I do note also that ppc(4) is not added to the puc devclass,
presumably for the same reason.  I'm also guessing things would work if
sio was a module too.

It seems odd to me that a module cannot add an in-kernel driver to it's
devclass, but at this point I'm out of my depth as far as figuring out
how to fix it goes.

Gavin

Gavin