i820 agp support ?

i820 agp support ?

[Nicolas Aspert]

Hello

It seems to me that the i820 chipset from Intel, which I have on my PC, 
is not supported by the 'agpgart' module. Looking at the source (from 
2.4.13) shows that there is support for i810, i815 and then skips to i830.
I have managed to use the module successfully with the nice 
'agp_try_unsupported=1' option (with a kernel 2.4.9 from RedHat), but 
still something remain unclear to me, namely "why is the i820 still in 
the 'unsupported' hardware ?".

Are there many major differences between i820 and the other Intel 
chipsets ?

Thanks in advance for answering.

Best regards.

Nicolas.

PS: please CC to me your answers/comments since I am not subscribed to 
the list.
-- 
Nicolas Aspert      Signal Processing Laboratory (LTS)
Swiss Federal Institute of Technology (EPFL)
Office:  ELE 237

Re: i820 agp support ?

[Robert Love]

On Wed, 2001-10-31 at 08:01, Nicolas Aspert wrote:
> It seems to me that the i820 chipset from Intel, which I have on my PC, 
> is not supported by the 'agpgart' module. Looking at the source (from 
> 2.4.13) shows that there is support for i810, i815 and then skips to i830.
> I have managed to use the module successfully with the nice 
> 'agp_try_unsupported=1' option (with a kernel 2.4.9 from RedHat), but 
> still something remain unclear to me, namely "why is the i820 still in 
> the 'unsupported' hardware ?".
> 
> Are there many major differences between i820 and the other Intel 
> chipsets ?
> 
> Thanks in advance for answering.

I will work on support for the i820 ... I don't believe there is any
particular reason we don't support it.  Please give me the output of

	/sbin/lspci -s 0 -v -n

on your i820 machine.

	Robert Love

Re: i820 agp support ?

[Nicolas Aspert]

Robert Love wrote:


> 
> I will work on support for the i820 ... I don't believe there is any
> particular reason we don't support it.  Please give me the output of
> 
> 	/sbin/lspci -s 0 -v -n
> 
> on your i820 machine.



Hello


Here is the output I get :


00:00.0 Class 0600: 8086:2500 (rev 03)
         Flags: bus master, fast devsel, latency 0
         Memory at f8000000 (32-bit, prefetchable) [size=64M]
         Capabilities: [a0] AGP version 2.0

01:00.0 Class 0300: 10de:0028 (rev 11)
         Subsystem: 1048:0c20
         Flags: bus master, 66Mhz, medium devsel, latency 248, IRQ 10
         Memory at f4000000 (32-bit, non-prefetchable) [size=16M]
         Memory at f6000000 (32-bit, prefetchable) [size=32M]
         Expansion ROM at <unassigned> [disabled] [size=64K]
         Capabilities: [60] Power Management version 1
         Capabilities: [44] AGP version 2.0

I was trying to tweak myself the agp code (well, mostly by copying the 
intel_generic_setup stuff to a intel_i820_setup stuff, but I guess there 
is a more clever way !). Maybe I can help with this ?

I guess that the device id's that must be added into 'agp.h' look like 
this :

#ifndef PCI_DEVICE_ID_INTEL_820_0
#define PCI_DEVICE_ID_INTEL_820_0       0x2500
#endif
/* [...] */
#ifndef PCI_DEVICE_ID_INTEL_820_1
#define PCI_DEVICE_ID_INTEL_820_1       0x250f
#endif

is it correct ?


Nicolas.
-- 
Nicolas Aspert      Signal Processing Laboratory (LTS)
Swiss Federal Institute of Technology (EPFL)