[Openchrome-devel] Ring Buffer for K8M890 and P4M900

[Bartosz Kosiorek]

Hi.
After I have enabled AGP DMA on K8M890 chipset and I had error:
      (EE) CHROME(0): [drm] Failed to initialize DMA ring-buffer: 22

I would like to solve this bug on this chipset.
I found in "via_dri.c" file, function "VIADRIRingBufferInit" which
initializate the ring-buffer.
I think the address could be incorrect for K8M890 and P4M900 chipset.

I would like to ask what is correct "reg_pause_addr" addres for K8M890
and P4M900 chipset?
Is the addres "pVIADRI->reg_pause_addr = 0x418;" is correct for K8M890
and P4M900 chipset?

I think K8M890 it is PCI_CHIP_VT3336 or PCI_CHIP_VT3230. What is
difference between it?

Here is the source code part of the function "VIADRIRingBufferInit":
         /*
         * Info frome code-snippet on DRI-DEVEL list; Erdi Chen.
         */

        switch (pVia->ChipId) {
            case PCI_CHIP_VT3314:
<== I think it is for VIA_VM800
            case PCI_CHIP_VT3259:
<== I think it is for VIA_PM800
                pVIADRI->reg_pause_addr = 0x40c;
                break;
            default:
                pVIADRI->reg_pause_addr = 0x418;                <== Is
this address is correct for  K8M890 and P4M900 ????????
                break;
        }

Best Regards
Bartosz Kosiorek