Re: 2.6.8.1-mm1 and Asus L3C : problematic change found, can be reverted.Real fix still missing

[Eric Valette]

Eric Valette wrote:
> Li, Shaohua wrote:
>
> > Eric,
> > The patch for bug 3049 has been in 2.6.8.1 and should fix the IO port
> > problem. If the Asus quirk is just because of IO port problem, I'd like
> > to remove it. Note PNP driver also reserves the IO port for the SMBus
> > and lets SMBus driver to use it. ACPI motherboard driver behaves the
> > same as PNP driver.
>
>
> Unfortunately, as I understand it, the fix is done to "unhide" the SMBus 
> that otherwyse is not seen but it has unexpected side effect of messing 
> ioports allocation/reservation. I guess lspci with and without the fix 
> could help to understand the problem. Here is the comment on top of the 
> function :

OK I've put my debugger hat and tried to go a little further. Here is an 
(I hope) interesting PCI tweaking session. For helping the readder here 
are the meaning of some value :
	1) 8086:248c : Intel Corp. 82801CAM ISA Bridge (LPC) (rev 02)
	2) 8086:2483 : the PCI ID for the i801 SMB bus
	3) 0xF2 the register offset used to enable the SBus in the ISA Bridge
	4) 0x20 = SMBBA = SMBbus base address in the i2c-i801.c file


root@pink-floyd:/home/valette# setpci -H1 -v -d 8086:248c 0xF2.W 
00:1f.0:f2 = 8409
root@pink-floyd:/home/valette# pcitweak -l  > 
pci_devices_list_without_enabling_SMBus 2>&1
root@pink-floyd:/home/valette# setpci -H1 -v -d 8086:248c 0xF2.W=8401 
00:1f.0:f2 8401
root@pink-floyd:/home/valette# pcitweak -l  > 
pci_devices_list_after_enabling_SMBus 2>&1
root@pink-floyd:/home/valette# diff 
pci_devices_list_without_enabling_SMBus 
pci_devices_list_after_enabling_SMBus
10a11
> PCI: 00:1f:3: chip 8086,2483 card 1043,1628 rev 02 class 0c,05,00 hdr 00
root@pink-floyd:/home/valette# setpci -H1 -v -d 8086:2483 20.w
00:1f.3:20 = e801

So my deduction are :
	1) The trick for enabling the SMBbus is working,
	2) The configured base IO range register value is e801 leading to 
theoritically request the e800 -> e808 IO region and curiously not e810 
as requested described by the DTST...

Now I do not understand why it get something else as io port region no 
that the ACPI fix for bug 3049 remove the IORESOURCE_BUSY flags


--
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  /  `                   	Eric Valette
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E-mail: eric.valette@xxxxxxx
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