SMBus controller

[Sean Bruno]

On Sat, 2014-06-14 at 12:08 -0700, Sean Bruno wrote: 
> I note that my TLenovo 61 has one of these:
> 
> ichsmb0 at pci0:0:31:3:	class=0x0c0500 card=0x20a917aa chip=0x283e8086
> rev=0x03 hdr=0x00
>     vendor     = 'Intel Corporation'
>     device     = '82801H (ICH8 Family) SMBus Controller'
>     class      = serial bus
>     subclass   = SMBus
> 
> 

So, there's something broken in the initialization of the driver and the
driver dependencies here.

If I load "smb.ko" by itself, no other modules are loaded (ichsmb,
smbus).  Should it?

If I load ichsmb, smbus is loaded, so that's good.  But, the first time
I do this, the driver seems to think I have 16 bus instances:


iicsmb0: <SMBus over I2C bridge> on iicbus0
iicsmb1: <SMBus over I2C bridge> on iicbus1
iicsmb2: <SMBus over I2C bridge> on iicbus2
iicsmb3: <SMBus over I2C bridge> on iicbus3
iicsmb4: <SMBus over I2C bridge> on iicbus4
iicsmb5: <SMBus over I2C bridge> on iicbus5
iicsmb6: <SMBus over I2C bridge> on iicbus6
iicsmb7: <SMBus over I2C bridge> on iicbus7
iicsmb8: <SMBus over I2C bridge> on iicbus8
iicsmb9: <SMBus over I2C bridge> on iicbus9
iicsmb10: <SMBus over I2C bridge> on iicbus10
iicsmb11: <SMBus over I2C bridge> on iicbus11
iicsmb12: <SMBus over I2C bridge> on iicbus12
iicsmb13: <SMBus over I2C bridge> on iicbus13
iicsmb14: <SMBus over I2C bridge> on iicbus14
iicsmb15: <SMBus over I2C bridge> on iicbus15
smbus0: <System Management Bus> on iicsmb0
smbus1: <System Management Bus> on iicsmb1
smbus2: <System Management Bus> on iicsmb2
smbus3: <System Management Bus> on iicsmb3
smbus4: <System Management Bus> on iicsmb4
smbus5: <System Management Bus> on iicsmb5
smbus6: <System Management Bus> on iicsmb6
smbus7: <System Management Bus> on iicsmb7
smbus8: <System Management Bus> on iicsmb8
smbus9: <System Management Bus> on iicsmb9
smbus10: <System Management Bus> on iicsmb10
smbus11: <System Management Bus> on iicsmb11
smbus12: <System Management Bus> on iicsmb12
smbus13: <System Management Bus> on iicsmb13
smbus14: <System Management Bus> on iicsmb14
smbus15: <System Management Bus> on iicsmb15

I then load smb.ko and I get no useful output from smbmsg -p.

If I try to acces /dev/smb1, ctrl-c it, unload all modules and then
reload them, I get completely different (and functional) behavior.  I
only get ONE smbus and I can poll "devices" there, even though I have no
idea what they are.

ichsmb0: <Intel 82801H (ICH8) SMBus controller> port 0x1c60-0x1c7f mem
0xfe227400-0xfe2274ff irq 23 at device 31.3 on pci0
smbus0: <System Management Bus> on ichsmb0
smb0: <SMBus generic I/O> on smbus0
root at bruno:/home/sbruno # smbmsg -p
Probing for devices on /dev/smb0:
Device @0x10: w
Device @0x88: rw
Device @0xa8: w
Device @0xaa: rw
Device @0xac: rw
Device @0xae: rw
Device @0xb8: rw
Device @0xc2: w
Device @0xc8: w






Right ... so, I did the following:

kldload ichsmb

This seems to know to bull in smbus.ko.

ichsmb0: <Intel 82801H (ICH8) SMBus controller> port 0x1c60-0x1c7f mem
0xfe227400-0xfe2274ff irq 23 at device 31.3 on pci0
smbus0: <System Management Bus> on ichsmb0


This doesn't really do anything useful, until I load "smb.ko":