PCI-ISA Bridge not operating

PCI-ISA Bridge not operating

[David Brigada]

Hi,

I'm working with the MSM800XEV board from Digital-Logic.  This board 
uses a Geode LX800 for a CPU and has the CS5536 companion board also 
installed.  The board works with an IT8888G IC that provides a PCI/ISA 
bridge to a PC/104 bus that is externally provided.

If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
goes low as expected, but the address doesn't come over the bus.  The 
DOS that I'm running doesn't seem to have any specific drivers for the 
chip, I'm guessing that the hardware should "just work" --- the IT8888G 
is designed to grab I/O requests in the ISA range off the PCI bus after 
a short delay if nothing else grabs them first.

I have a feeling that it has something to do with the CS5536 companion 
chip, as it seems as though there is a driver for a PCI/ISA bridge on 
that chip, though I can't get much detail from AMD's datasheet on that 
functionality.  I do know that on the MSM800XEV, any such functionality 
is wired to the IT8888G, not the CS5536.

There are two kernel config options related to the PCI IDs of the parts 
of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.

In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.

Any ideas?

Thanks,
David Brigada

Re: PCI-ISA Bridge not operating

[Jordan Crouse]

On 11/07/08 10:58 -0400, David Brigada wrote:
> Hi,
> 
> I'm working with the MSM800XEV board from Digital-Logic.  This board 
> uses a Geode LX800 for a CPU and has the CS5536 companion board also 
> installed.  The board works with an IT8888G IC that provides a PCI/ISA 
> bridge to a PC/104 bus that is externally provided.
> 
> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
> signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
> goes low as expected, but the address doesn't come over the bus.  The 
> DOS that I'm running doesn't seem to have any specific drivers for the 
> chip, I'm guessing that the hardware should "just work" --- the IT8888G 
> is designed to grab I/O requests in the ISA range off the PCI bus after 
> a short delay if nothing else grabs them first.
> 
> I have a feeling that it has something to do with the CS5536 companion 
> chip, as it seems as though there is a driver for a PCI/ISA bridge on 
> that chip, though I can't get much detail from AMD's datasheet on that 
> functionality.  I do know that on the MSM800XEV, any such functionality 
> is wired to the IT8888G, not the CS5536.
> 
> There are two kernel config options related to the PCI IDs of the parts 
> of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
> CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.
> 
> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.
> 
> Any ideas?

ISA should indeed "just work".  The only thing I'm wondering is if
the kernel is interfering (it shouldn't).  I assume that since it works
in FreeDOS that there is no possibility that something on the PCI bus
is grabbing the cycles instead.

How are you trying to access the device in Linux?  Through a kernel module
or a user application running as root?

Jordan

-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

Re: PCI-ISA Bridge not operating

[David Brigada]

Jordan Crouse wrote:
> On 11/07/08 10:58 -0400, David Brigada wrote:
>> Hi,
>>
>> I'm working with the MSM800XEV board from Digital-Logic.  This board 
>> uses a Geode LX800 for a CPU and has the CS5536 companion board also 
>> installed.  The board works with an IT8888G IC that provides a PCI/ISA 
>> bridge to a PC/104 bus that is externally provided.
>>
>> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
>> signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
>> goes low as expected, but the address doesn't come over the bus.  The 
>> DOS that I'm running doesn't seem to have any specific drivers for the 
>> chip, I'm guessing that the hardware should "just work" --- the IT8888G 
>> is designed to grab I/O requests in the ISA range off the PCI bus after 
>> a short delay if nothing else grabs them first.
>>
>> I have a feeling that it has something to do with the CS5536 companion 
>> chip, as it seems as though there is a driver for a PCI/ISA bridge on 
>> that chip, though I can't get much detail from AMD's datasheet on that 
>> functionality.  I do know that on the MSM800XEV, any such functionality 
>> is wired to the IT8888G, not the CS5536.
>>
>> There are two kernel config options related to the PCI IDs of the parts 
>> of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
>> CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.
>>
>> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.
>>
>> Any ideas?
> 
> ISA should indeed "just work".  The only thing I'm wondering is if
> the kernel is interfering (it shouldn't).  I assume that since it works
> in FreeDOS that there is no possibility that something on the PCI bus
> is grabbing the cycles instead.

That's what I'm thinking --- that the CS5536 PCI/ISA bridge is claiming 
the cycles.

> How are you trying to access the device in Linux?  Through a kernel module
> or a user application running as root?

I've tried both.  I have a kernel module that I wrote for the hardware. 
  When I couldn't get that working, I tried looping some code that keeps 
touching the same I/O port that I'm using.

> Jordan
> 

Dave

Re: PCI-ISA Bridge not operating

[David Brigada]

David Brigada wrote:
> Jordan Crouse wrote:
>> On 11/07/08 10:58 -0400, David Brigada wrote:
>>> Hi,
>>>
>>> I'm working with the MSM800XEV board from Digital-Logic.  This board 
>>> uses a Geode LX800 for a CPU and has the CS5536 companion board also 
>>> installed.  The board works with an IT8888G IC that provides a PCI/ISA 
>>> bridge to a PC/104 bus that is externally provided.
>>>
>>> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
>>> signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
>>> goes low as expected, but the address doesn't come over the bus.  The 
>>> DOS that I'm running doesn't seem to have any specific drivers for the 
>>> chip, I'm guessing that the hardware should "just work" --- the IT8888G 
>>> is designed to grab I/O requests in the ISA range off the PCI bus after 
>>> a short delay if nothing else grabs them first.
>>>
>>> I have a feeling that it has something to do with the CS5536 companion 
>>> chip, as it seems as though there is a driver for a PCI/ISA bridge on 
>>> that chip, though I can't get much detail from AMD's datasheet on that 
>>> functionality.  I do know that on the MSM800XEV, any such functionality 
>>> is wired to the IT8888G, not the CS5536.
>>>
>>> There are two kernel config options related to the PCI IDs of the parts 
>>> of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
>>> CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.
>>>
>>> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.
>>>
>>> Any ideas?
>> ISA should indeed "just work".  The only thing I'm wondering is if
>> the kernel is interfering (it shouldn't).  I assume that since it works
>> in FreeDOS that there is no possibility that something on the PCI bus
>> is grabbing the cycles instead.
> 
> That's what I'm thinking --- that the CS5536 PCI/ISA bridge is claiming 
> the cycles.
> 
>> How are you trying to access the device in Linux?  Through a kernel module
>> or a user application running as root?
> 
> I've tried both.  I have a kernel module that I wrote for the hardware. 
>   When I couldn't get that working, I tried looping some code that keeps 
> touching the same I/O port that I'm using.
> 
>> Jordan
>>
> 
> Dave

Looking through the documentation for the CS5536, in the "CS56536 
Companion Device Data Book," section 5.2.8, it says the following:

 > If the SDOFF (Subtractive Decode Off) bit in the GLPCI_MSR_CTRL (MSR
 > 51000010h[10]) is cleared (reset value), any PCI transaction, other
 > than Configuration Read/Write, Interrupt Acknowledge, and Special
 > Cycle transactions, not claimed by any device (i.3., not asserting
 > DEVSEL#) within the default active decode cycles (three cycles
 > immediately after FRAME# being asserted) will be accepted by GLPCI_SB
 > at the fourth clock edge.

This is the same behavior that the IT8888G chip uses --- it waits three 
cycles for another device to claim it and then passes the transaction 
along.  I'm guessing that the CS5536 might be grabbing it (maybe it's 
electrically closer, or the logic is more optimized) before the IT8888G 
can handle it.

Does this seem feasible as to what could be happening?

Dave

Re: PCI-ISA Bridge not operating

[Jordan Crouse]

On 11/07/08 14:58 -0400, David Brigada wrote:
> David Brigada wrote:
> > Jordan Crouse wrote:
> >> On 11/07/08 10:58 -0400, David Brigada wrote:
> >>> Hi,
> >>>
> >>> I'm working with the MSM800XEV board from Digital-Logic.  This board 
> >>> uses a Geode LX800 for a CPU and has the CS5536 companion board also 
> >>> installed.  The board works with an IT8888G IC that provides a PCI/ISA 
> >>> bridge to a PC/104 bus that is externally provided.
> >>>
> >>> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
> >>> signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
> >>> goes low as expected, but the address doesn't come over the bus.  The 
> >>> DOS that I'm running doesn't seem to have any specific drivers for the 
> >>> chip, I'm guessing that the hardware should "just work" --- the IT8888G 
> >>> is designed to grab I/O requests in the ISA range off the PCI bus after 
> >>> a short delay if nothing else grabs them first.
> >>>
> >>> I have a feeling that it has something to do with the CS5536 companion 
> >>> chip, as it seems as though there is a driver for a PCI/ISA bridge on 
> >>> that chip, though I can't get much detail from AMD's datasheet on that 
> >>> functionality.  I do know that on the MSM800XEV, any such functionality 
> >>> is wired to the IT8888G, not the CS5536.
> >>>
> >>> There are two kernel config options related to the PCI IDs of the parts 
> >>> of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
> >>> CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.
> >>>
> >>> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.
> >>>
> >>> Any ideas?
> >> ISA should indeed "just work".  The only thing I'm wondering is if
> >> the kernel is interfering (it shouldn't).  I assume that since it works
> >> in FreeDOS that there is no possibility that something on the PCI bus
> >> is grabbing the cycles instead.
> > 
> > That's what I'm thinking --- that the CS5536 PCI/ISA bridge is claiming 
> > the cycles.
> > 
> >> How are you trying to access the device in Linux?  Through a kernel module
> >> or a user application running as root?
> > 
> > I've tried both.  I have a kernel module that I wrote for the hardware. 
> >   When I couldn't get that working, I tried looping some code that keeps 
> > touching the same I/O port that I'm using.
> > 
> >> Jordan
> >>
> > 
> > Dave
> 
> Looking through the documentation for the CS5536, in the "CS56536 
> Companion Device Data Book," section 5.2.8, it says the following:
> 
>  > If the SDOFF (Subtractive Decode Off) bit in the GLPCI_MSR_CTRL (MSR
>  > 51000010h[10]) is cleared (reset value), any PCI transaction, other
>  > than Configuration Read/Write, Interrupt Acknowledge, and Special
>  > Cycle transactions, not claimed by any device (i.3., not asserting
>  > DEVSEL#) within the default active decode cycles (three cycles
>  > immediately after FRAME# being asserted) will be accepted by GLPCI_SB
>  > at the fourth clock edge.
> 
> This is the same behavior that the IT8888G chip uses --- it waits three 
> cycles for another device to claim it and then passes the transaction 
> along.  I'm guessing that the CS5536 might be grabbing it (maybe it's 
> electrically closer, or the logic is more optimized) before the IT8888G 
> can handle it.
> 
> Does this seem feasible as to what could be happening?

Sure, but then why does FreeDOS work?  It shouldn't be any different
when the bits hit the line.

Jordan
-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

Re: PCI-ISA Bridge not operating

[David Brigada]

Jordan Crouse wrote:
> On 11/07/08 14:58 -0400, David Brigada wrote:
>> David Brigada wrote:
>>> Jordan Crouse wrote:
>>>> On 11/07/08 10:58 -0400, David Brigada wrote:
>>>>> Hi,
>>>>>
>>>>> I'm working with the MSM800XEV board from Digital-Logic.  This board 
>>>>> uses a Geode LX800 for a CPU and has the CS5536 companion board also 
>>>>> installed.  The board works with an IT8888G IC that provides a PCI/ISA 
>>>>> bridge to a PC/104 bus that is externally provided.
>>>>>
>>>>> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
>>>>> signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
>>>>> goes low as expected, but the address doesn't come over the bus.  The 
>>>>> DOS that I'm running doesn't seem to have any specific drivers for the 
>>>>> chip, I'm guessing that the hardware should "just work" --- the IT8888G 
>>>>> is designed to grab I/O requests in the ISA range off the PCI bus after 
>>>>> a short delay if nothing else grabs them first.
>>>>>
>>>>> I have a feeling that it has something to do with the CS5536 companion 
>>>>> chip, as it seems as though there is a driver for a PCI/ISA bridge on 
>>>>> that chip, though I can't get much detail from AMD's datasheet on that 
>>>>> functionality.  I do know that on the MSM800XEV, any such functionality 
>>>>> is wired to the IT8888G, not the CS5536.
>>>>>
>>>>> There are two kernel config options related to the PCI IDs of the parts 
>>>>> of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
>>>>> CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.
>>>>>
>>>>> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.
>>>>>
>>>>> Any ideas?
>>>> ISA should indeed "just work".  The only thing I'm wondering is if
>>>> the kernel is interfering (it shouldn't).  I assume that since it works
>>>> in FreeDOS that there is no possibility that something on the PCI bus
>>>> is grabbing the cycles instead.
>>> That's what I'm thinking --- that the CS5536 PCI/ISA bridge is claiming 
>>> the cycles.
>>>
>>>> How are you trying to access the device in Linux?  Through a kernel module
>>>> or a user application running as root?
>>> I've tried both.  I have a kernel module that I wrote for the hardware. 
>>>   When I couldn't get that working, I tried looping some code that keeps 
>>> touching the same I/O port that I'm using.
>>>
>>>> Jordan
>>>>
>>> Dave
>> Looking through the documentation for the CS5536, in the "CS56536 
>> Companion Device Data Book," section 5.2.8, it says the following:
>>
>>  > If the SDOFF (Subtractive Decode Off) bit in the GLPCI_MSR_CTRL (MSR
>>  > 51000010h[10]) is cleared (reset value), any PCI transaction, other
>>  > than Configuration Read/Write, Interrupt Acknowledge, and Special
>>  > Cycle transactions, not claimed by any device (i.3., not asserting
>>  > DEVSEL#) within the default active decode cycles (three cycles
>>  > immediately after FRAME# being asserted) will be accepted by GLPCI_SB
>>  > at the fourth clock edge.
>>
>> This is the same behavior that the IT8888G chip uses --- it waits three 
>> cycles for another device to claim it and then passes the transaction 
>> along.  I'm guessing that the CS5536 might be grabbing it (maybe it's 
>> electrically closer, or the logic is more optimized) before the IT8888G 
>> can handle it.
>>
>> Does this seem feasible as to what could be happening?
> 
> Sure, but then why does FreeDOS work?  It shouldn't be any different
> when the bits hit the line.
> 
> Jordan

That *is* puzzling.  When I do lspci, the entry for the IT8888G does not 
appear.  I don't have much experience with PCI internals.  Would that be 
because there is no driver for it in the kernel, or is there something 
more insidious afoot?

Dave

Re: PCI-ISA Bridge not operating

[Jordan Crouse]

On 11/07/08 16:14 -0400, David Brigada wrote:
> Jordan Crouse wrote:
> > On 11/07/08 14:58 -0400, David Brigada wrote:
> >> David Brigada wrote:
> >>> Jordan Crouse wrote:
> >>>> On 11/07/08 10:58 -0400, David Brigada wrote:
> >>>>> Hi,
> >>>>>
> >>>>> I'm working with the MSM800XEV board from Digital-Logic.  This board 
> >>>>> uses a Geode LX800 for a CPU and has the CS5536 companion board also 
> >>>>> installed.  The board works with an IT8888G IC that provides a PCI/ISA 
> >>>>> bridge to a PC/104 bus that is externally provided.
> >>>>>
> >>>>> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
> >>>>> signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
> >>>>> goes low as expected, but the address doesn't come over the bus.  The 
> >>>>> DOS that I'm running doesn't seem to have any specific drivers for the 
> >>>>> chip, I'm guessing that the hardware should "just work" --- the IT8888G 
> >>>>> is designed to grab I/O requests in the ISA range off the PCI bus after 
> >>>>> a short delay if nothing else grabs them first.
> >>>>>
> >>>>> I have a feeling that it has something to do with the CS5536 companion 
> >>>>> chip, as it seems as though there is a driver for a PCI/ISA bridge on 
> >>>>> that chip, though I can't get much detail from AMD's datasheet on that 
> >>>>> functionality.  I do know that on the MSM800XEV, any such functionality 
> >>>>> is wired to the IT8888G, not the CS5536.
> >>>>>
> >>>>> There are two kernel config options related to the PCI IDs of the parts 
> >>>>> of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
> >>>>> CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.
> >>>>>
> >>>>> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.
> >>>>>
> >>>>> Any ideas?
> >>>> ISA should indeed "just work".  The only thing I'm wondering is if
> >>>> the kernel is interfering (it shouldn't).  I assume that since it works
> >>>> in FreeDOS that there is no possibility that something on the PCI bus
> >>>> is grabbing the cycles instead.
> >>> That's what I'm thinking --- that the CS5536 PCI/ISA bridge is claiming 
> >>> the cycles.
> >>>
> >>>> How are you trying to access the device in Linux?  Through a kernel module
> >>>> or a user application running as root?
> >>> I've tried both.  I have a kernel module that I wrote for the hardware. 
> >>>   When I couldn't get that working, I tried looping some code that keeps 
> >>> touching the same I/O port that I'm using.
> >>>
> >>>> Jordan
> >>>>
> >>> Dave
> >> Looking through the documentation for the CS5536, in the "CS56536 
> >> Companion Device Data Book," section 5.2.8, it says the following:
> >>
> >>  > If the SDOFF (Subtractive Decode Off) bit in the GLPCI_MSR_CTRL (MSR
> >>  > 51000010h[10]) is cleared (reset value), any PCI transaction, other
> >>  > than Configuration Read/Write, Interrupt Acknowledge, and Special
> >>  > Cycle transactions, not claimed by any device (i.3., not asserting
> >>  > DEVSEL#) within the default active decode cycles (three cycles
> >>  > immediately after FRAME# being asserted) will be accepted by GLPCI_SB
> >>  > at the fourth clock edge.
> >>
> >> This is the same behavior that the IT8888G chip uses --- it waits three 
> >> cycles for another device to claim it and then passes the transaction 
> >> along.  I'm guessing that the CS5536 might be grabbing it (maybe it's 
> >> electrically closer, or the logic is more optimized) before the IT8888G 
> >> can handle it.
> >>
> >> Does this seem feasible as to what could be happening?
> > 
> > Sure, but then why does FreeDOS work?  It shouldn't be any different
> > when the bits hit the line.
> > 
> > Jordan
> 
> That *is* puzzling.  When I do lspci, the entry for the IT8888G does not 
> appear.  I don't have much experience with PCI internals.  Would that be 
> because there is no driver for it in the kernel, or is there something 
> more insidious afoot?

Well - the first step would be to get a dmesg output.  if the kernel
is doing anything to the device at all, the dmesg will show it.

Jordan

-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

Re: PCI-ISA Bridge not operating

[David Brigada]

[-- Attachment #1: Type: text/plain, Size: 4394 bytes --]

Jordan Crouse wrote:
> On 11/07/08 16:14 -0400, David Brigada wrote:
>> Jordan Crouse wrote:
>>> On 11/07/08 14:58 -0400, David Brigada wrote:
>>>> David Brigada wrote:
>>>>> Jordan Crouse wrote:
>>>>>> On 11/07/08 10:58 -0400, David Brigada wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> I'm working with the MSM800XEV board from Digital-Logic.  This board 
>>>>>>> uses a Geode LX800 for a CPU and has the CS5536 companion board also 
>>>>>>> installed.  The board works with an IT8888G IC that provides a PCI/ISA 
>>>>>>> bridge to a PC/104 bus that is externally provided.
>>>>>>>
>>>>>>> If I boot with FreeDOS, I can twiddle I/O ports, and the proper ISA 
>>>>>>> signaling comes over the PC/104 bus.  In Linux, the /IOW or /IOR line 
>>>>>>> goes low as expected, but the address doesn't come over the bus.  The 
>>>>>>> DOS that I'm running doesn't seem to have any specific drivers for the 
>>>>>>> chip, I'm guessing that the hardware should "just work" --- the IT8888G 
>>>>>>> is designed to grab I/O requests in the ISA range off the PCI bus after 
>>>>>>> a short delay if nothing else grabs them first.
>>>>>>>
>>>>>>> I have a feeling that it has something to do with the CS5536 companion 
>>>>>>> chip, as it seems as though there is a driver for a PCI/ISA bridge on 
>>>>>>> that chip, though I can't get much detail from AMD's datasheet on that 
>>>>>>> functionality.  I do know that on the MSM800XEV, any such functionality 
>>>>>>> is wired to the IT8888G, not the CS5536.
>>>>>>>
>>>>>>> There are two kernel config options related to the PCI IDs of the parts 
>>>>>>> of the device that handle the ISA bus, CONFIG_SCx200_ACB and 
>>>>>>> CONFIG_CS5535_GPIO.  I've tried disabling both, but it doesn't seem to help.
>>>>>>>
>>>>>>> In lspci, the CS5536 PCI/ISA bridge is shown, but not the IT8888G.
>>>>>>>
>>>>>>> Any ideas?
>>>>>> ISA should indeed "just work".  The only thing I'm wondering is if
>>>>>> the kernel is interfering (it shouldn't).  I assume that since it works
>>>>>> in FreeDOS that there is no possibility that something on the PCI bus
>>>>>> is grabbing the cycles instead.
>>>>> That's what I'm thinking --- that the CS5536 PCI/ISA bridge is claiming 
>>>>> the cycles.
>>>>>
>>>>>> How are you trying to access the device in Linux?  Through a kernel module
>>>>>> or a user application running as root?
>>>>> I've tried both.  I have a kernel module that I wrote for the hardware. 
>>>>>   When I couldn't get that working, I tried looping some code that keeps 
>>>>> touching the same I/O port that I'm using.
>>>>>
>>>>>> Jordan
>>>>>>
>>>>> Dave
>>>> Looking through the documentation for the CS5536, in the "CS56536 
>>>> Companion Device Data Book," section 5.2.8, it says the following:
>>>>
>>>>  > If the SDOFF (Subtractive Decode Off) bit in the GLPCI_MSR_CTRL (MSR
>>>>  > 51000010h[10]) is cleared (reset value), any PCI transaction, other
>>>>  > than Configuration Read/Write, Interrupt Acknowledge, and Special
>>>>  > Cycle transactions, not claimed by any device (i.3., not asserting
>>>>  > DEVSEL#) within the default active decode cycles (three cycles
>>>>  > immediately after FRAME# being asserted) will be accepted by GLPCI_SB
>>>>  > at the fourth clock edge.
>>>>
>>>> This is the same behavior that the IT8888G chip uses --- it waits three 
>>>> cycles for another device to claim it and then passes the transaction 
>>>> along.  I'm guessing that the CS5536 might be grabbing it (maybe it's 
>>>> electrically closer, or the logic is more optimized) before the IT8888G 
>>>> can handle it.
>>>>
>>>> Does this seem feasible as to what could be happening?
>>> Sure, but then why does FreeDOS work?  It shouldn't be any different
>>> when the bits hit the line.
>>>
>>> Jordan
>> That *is* puzzling.  When I do lspci, the entry for the IT8888G does not 
>> appear.  I don't have much experience with PCI internals.  Would that be 
>> because there is no driver for it in the kernel, or is there something 
>> more insidious afoot?
> 
> Well - the first step would be to get a dmesg output.  if the kernel
> is doing anything to the device at all, the dmesg will show it.
> 
> Jordan
> 

[Sorry, Jordan about the double-mail]

The dmesg output doesn't have anything related to the device.  I have 
attached my dmesg output for completeness.  Ignore the last four lines, 
that's my testing.  The PCI ID of the IT8888G is 1283:8888.

Dave

[-- Attachment #2: dmesg-out --]
[-- Type: text/plain, Size: 10589 bytes --]

Linux version 2.6.26-rc9 (root@brigad-thz-linux) (gcc version 4.3.1 (Debian 4.3.1-2) ) #2 Fri Jul 11 06:23:00 EDT 2008
PAT not supported by CPU.
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
 BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000000e7b0000 (usable)
 BIOS-e820: 000000000e7b0000 - 000000000e7bffc0 (ACPI data)
 BIOS-e820: 000000000e7bffc0 - 000000000e7c0000 (ACPI NVS)
 BIOS-e820: 0000000040400000 - 0000000040440004 (reserved)
 BIOS-e820: 00000000f0000000 - 0000000100000000 (reserved)
231MB LOWMEM available.
Entering add_active_range(0, 0, 59312) 0 entries of 256 used
Zone PFN ranges:
  DMA             0 ->     4096
  Normal       4096 ->    59312
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
    0:        0 ->    59312
On node 0 totalpages: 59312
  DMA zone: 32 pages used for memmap
  DMA zone: 0 pages reserved
  DMA zone: 4064 pages, LIFO batch:0
  Normal zone: 432 pages used for memmap
  Normal zone: 54784 pages, LIFO batch:15
  Movable zone: 0 pages used for memmap
DMI not present or invalid.
ACPI: RSDP 000E9010, 0014 (r0 OID_00)
ACPI: RSDT 0E7B2AE0, 0030 (r1 AMD    RSDT_000 31303030 AMD  31303030)
ACPI: FACP 0E7B29E0, 0084 (r1 AMD    FACP_000 31303030 AMD  31303030)
ACPI: DSDT 0E7B0000, 29D6 (r1 INSYDE CS553x       1007 INTL 20030122)
ACPI: FACS 0E7BFFC0, 0040
ACPI: BOOT 0E7B2A70, 0028 (r1 AMD    BOOT_000 31303030 AMD  31303030)
ACPI: DBGP 0E7B2AA0, 0034 (r1 AMD    DBGP_000 31303030 AMD  31303030)
ACPI: PM-Timer IO Port: 0x9c10
Allocating PCI resources starting at 50000000 (gap: 40440004:afbbfffc)
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 58848
Kernel command line: root=/dev/hdb1 ro 
Initializing CPU#0
PID hash table entries: 1024 (order: 10, 4096 bytes)
Detected 499.585 MHz processor.
Console: colour VGA+ 80x25
console [tty0] enabled
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 231248k/237248k available (2085k kernel code, 5428k reserved, 846k data, 176k init, 0k highmem)
virtual kernel memory layout:
    fixmap  : 0xffff6000 - 0xfffff000   (  36 kB)
    vmalloc : 0xcf000000 - 0xffff4000   ( 783 MB)
    lowmem  : 0xc0000000 - 0xce7b0000   ( 231 MB)
      .init : 0xc03e0000 - 0xc040c000   ( 176 kB)
      .data : 0xc03095f2 - 0xc03dcfd8   ( 846 kB)
      .text : 0xc0100000 - 0xc03095f2   (2085 kB)
Checking if this processor honours the WP bit even in supervisor mode...Ok.
CPA: page pool initialized 1 of 1 pages preallocated
Calibrating delay using timer specific routine.. 1000.29 BogoMIPS (lpj=500145)
Security Framework initialized
SELinux:  Disabled at boot.
Capability LSM initialized
Mount-cache hash table entries: 512
CPU: L1 I Cache: 64K (32 bytes/line), D cache 64K (32 bytes/line)
CPU: L2 Cache: 128K (32 bytes/line)
CPU: AMD Geode(TM) Integrated Processor by AMD PCS stepping 02
Checking 'hlt' instruction... OK.
Freeing SMP alternatives: 0k freed
ACPI: Core revision 20080321
ACPI: setting ELCR to 0200 (from 0c00)
net_namespace: 640 bytes
NET: Registered protocol family 16
geode-mfgpt:  0 MFGPT timers available.
mfgpt-timer:  Could not allocate a MFPGT timer
ACPI: bus type pci registered
PCI: PCI BIOS revision 2.10 entry at 0xff157, last bus=0
PCI: Using configuration type 1 for base access
Setting up standard PCI resources
ACPI: EC: Look up EC in DSDT
ACPI: Interpreter enabled
ACPI: (supports S0 S1 S3 S5)
ACPI: Using PIC for interrupt routing
ACPI: PCI Root Bridge [PCI0] (0000:00)
ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT]
ACPI: PCI Interrupt Link [LNKA] (IRQs *10)
ACPI: PCI Interrupt Link [LNKB] (IRQs *11)
ACPI: PCI Interrupt Link [LNKC] (IRQs *10)
ACPI: PCI Interrupt Link [LNKD] (IRQs *11)
Linux Plug and Play Support v0.97 (c) Adam Belay
pnp: PnP ACPI init
ACPI: bus type pnp registered
pnp: PnP ACPI: found 13 devices
ACPI: ACPI bus type pnp unregistered
PnPBIOS: Disabled by ACPI PNP
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
PCI: Using ACPI for IRQ routing
Switched to high resolution mode on CPU 0
ACPI: RTC can wake from S4
system 00:03: iomem range 0x0-0x9ffff could not be reserved
system 00:03: iomem range 0xe0000-0xfffff could not be reserved
system 00:03: iomem range 0x100000-0xe7affff could not be reserved
system 00:03: iomem range 0x40400000-0x4041ffff could not be reserved
system 00:03: iomem range 0xf0000000-0xffffffff could not be reserved
NET: Registered protocol family 2
IP route cache hash table entries: 2048 (order: 1, 8192 bytes)
TCP established hash table entries: 8192 (order: 4, 65536 bytes)
TCP bind hash table entries: 8192 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
TCP reno registered
NET: Registered protocol family 1
Simple Boot Flag at 0x3f set to 0x1
audit: initializing netlink socket (disabled)
type=2000 audit(1215772026.266:1): initialized
Total HugeTLB memory allocated, 0
msgmni has been set to 452
io scheduler noop registered
io scheduler cfq registered (default)
pci 0000:00:01.1: Boot video device
pci 0000:00:13.0: Firmware left e100 interrupts enabled; disabling
ACPI: PCI Interrupt Link [LNKA] enabled at IRQ 10
PCI: setting IRQ 10 as level-triggered
ACPI: PCI Interrupt 0000:00:01.1[A] -> Link [LNKA] -> GSI 10 (level, low) -> IRQ 10
lxfb 0000:00:01.1: 24576 KB of video memory at 0x50000000
Console: switching to colour frame buffer device 60x34
fb0: Geode LX frame buffer device
isapnp: Scanning for PnP cards...
isapnp: No Plug & Play device found
AMD Geode RNG detected
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
00:0a: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
00:0b: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
brd: module loaded
e100: Intel(R) PRO/100 Network Driver, 3.5.23-k4-NAPI
e100: Copyright(c) 1999-2006 Intel Corporation
ACPI: PCI Interrupt 0000:00:13.0[A] -> Link [LNKA] -> GSI 10 (level, low) -> IRQ 10
e100: eth0: e100_probe: addr 0xefb00000, irq 10, MAC addr 00:30:59:03:07:e8
Uniform Multi-Platform E-IDE driver
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
AMD5536: 0000:00:0f.2 (rev 01) UDMA100 controller
AMD5536: IDE controller (0x1022:0x209a rev 0x01) at  PCI slot 0000:00:0f.2
AMD5536: not 100% native mode: will probe irqs later
AMD5536: IDE port disabled
    ide0: BM-DMA at 0xeff0-0xeff7
Probing IDE interface ide0...
hdb: CF CARD 2GB, ATA DISK drive
hdb: host max PIO5 wanted PIO255(auto-tune) selected PIO2
hdb: host side 80-wire cable detection failed, limiting max speed to UDMA33
hdb: UDMA/33 mode selected
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide_generic: please use "probe_mask=0x3f" module parameter for probing all legacy ISA IDE ports
ide_generic: I/O resource 0x1F0-0x1F7 not free.
ide_generic: I/O resource 0x170-0x177 not free.
hdb: max request size: 128KiB
hdb: 3915072 sectors (2004 MB) w/1KiB Cache, CHS=3884/16/63
 hdb: hdb1
ide-floppy driver 1.00
ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 11
PCI: setting IRQ 11 as level-triggered
ACPI: PCI Interrupt 0000:00:0f.5[D] -> Link [LNKD] -> GSI 11 (level, low) -> IRQ 11
PCI: Setting latency timer of device 0000:00:0f.5 to 64
ehci_hcd 0000:00:0f.5: EHCI Host Controller
ehci_hcd 0000:00:0f.5: new USB bus registered, assigned bus number 1
ehci_hcd 0000:00:0f.5: irq 11, io mem 0xefc00000
ehci_hcd 0000:00:0f.5: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 4 ports detected
usbcore: registered new interface driver libusual
PNP: PS/2 Controller [PNP0303:KBC,PNP0f13:PS2M] at 0x60,0x64 irq 1,12
serio: i8042 KBD port at 0x60,0x64 irq 1
serio: i8042 AUX port at 0x60,0x64 irq 12
mice: PS/2 mouse device common for all mice
i2c /dev entries driver
input: AT Translated Set 2 keyboard as /class/input/input0
geodewdt:  No timers were available
cpuidle: using governor ladder
cpuidle: using governor menu
ACPI: PCI Interrupt 0000:00:01.2[A] -> Link [LNKA] -> GSI 10 (level, low) -> IRQ 10
geode-aes: GEODE AES engine enabled.
Advanced Linux Sound Architecture Driver Version 1.0.16.
ACPI: PCI Interrupt Link [LNKB] enabled at IRQ 11
ACPI: PCI Interrupt 0000:00:0f.3[B] -> Link [LNKB] -> GSI 11 (level, low) -> IRQ 11
PCI: Setting latency timer of device 0000:00:0f.3 to 64
Failure reading codec reg 0x7e,Last value=0x7e805375
Failure reading codec reg 0x7e,Last value=0x7e805375
ALSA device list:
  #0: CS5535 Audio cs5535audio at 0xdf80, irq 11
TCP bic registered
NET: Registered protocol family 10
lo: Disabled Privacy Extensions
NET: Registered protocol family 17
Using IPI Shortcut mode
registered taskstats version 1
kjournald starting.  Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
VFS: Mounted root (ext3 filesystem) readonly.
Freeing unused kernel memory: 176k freed
ACPI: CPU0 (power states: C1[C1] C2[C2])
ACPI: ACPI0007:00 is registered as cooling_device0
ACPI: Processor [CPU0] (supports 16 throttling states)
input: Power Button (FF) as /class/input/input1
ACPI: Power Button (FF) [PWRF]
input: Sleep Button (CM) as /class/input/input2
ACPI: Sleep Button (CM) [SLPB]
ACPI: AC Adapter [AC] (on-line)
ohci_hcd: 2006 August 04 USB 1.1 'Open' Host Controller (OHCI) Driver
ACPI: PCI Interrupt 0000:00:0f.4[D] -> Link [LNKD] -> GSI 11 (level, low) -> IRQ 11
PCI: Setting latency timer of device 0000:00:0f.4 to 64
ohci_hcd 0000:00:0f.4: OHCI Host Controller
ohci_hcd 0000:00:0f.4: new USB bus registered, assigned bus number 2
ohci_hcd 0000:00:0f.4: irq 11, io mem 0xeff00000
usb usb2: configuration #1 chosen from 1 choice
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 4 ports detected
input: PC Speaker as /class/input/input3
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
parport_pc 00:0c: disabled
parport_pc: probe of 00:0c failed with error -22
Marking TSC unstable due to: TSC halts in idle.
EXT3 FS on hdb1, internal journal
loop: module loaded
ADDRCONF(NETDEV_UP): eth1: link is not ready
e100: eth1: e100_watchdog: link up, 100Mbps, full-duplex
ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
eth1: no IPv6 routers present
miniz_ts.c: Allocated character device at (252, 0)
input: Unspecified device as /class/input/input4
miniz_ts.c: Allocated character device at (252, 0)
input: Unspecified device as /class/input/input5

Re: PCI-ISA Bridge not operating

[Jordan Crouse]

On 11/07/08 16:31 -0400, David Brigada wrote:

<snip>
> >> That *is* puzzling.  When I do lspci, the entry for the IT8888G does not 
> >> appear.  I don't have much experience with PCI internals.  Would that be 
> >> because there is no driver for it in the kernel, or is there something 
> >> more insidious afoot?
> > 
> > Well - the first step would be to get a dmesg output.  if the kernel
> > is doing anything to the device at all, the dmesg will show it.
> 
> The dmesg output doesn't have anything related to the device.  I have 
> attached my dmesg output for completeness.  Ignore the last four lines, 
> that's my testing.  The PCI ID of the IT8888G is 1283:8888.

Okay - interesting.  Can you try lcpci with direct hardware access?
By default lspci only lists those devices that Linux found and
enumerated.  Direct hardware access does the CF8/CFC dance.  If 
we find it that way, then its a hunt to figure out why Linux silently
discarded it.  Also, check the I/O ports you are trying to access in
/proc/ioports to see if anybody has claimed them.

Jordan