Alan Cox wrote: >> I now have an AM3 based DFI DK 790FXB-M3H5 motherboard. This board has 3 regular >> PCI slots and 3 PCI-E (16x) slots. I also have a PCI-E (x4) version of the VMIC-5565 >> reflective memory card in one of the PCI-E slots and our gpiohsd card in one of the regular >> PCI slots. All on the motherboard. No expansion slots being used. However I cannot get >> data from our gpiohsd into the PCI-E VMIC-5565 cards memory. I can certainly get the data there >> from a userland buffer, no problem. Just not from one card to the other directly. Oh and when >> I put the regular PCI version of the VMIC into one of the regular PCI slots everything works >> as expected. They are then both on the same PCI bus and no bridges are involved though. > > Have you verified with the vendor that such DMA works properly ? There is > a long history of there being boards where some device to device DMA > exploded or vanished. The arrival of PCI capture cards doing direct to > video DMA cleaned the world up (eg the BT848) but I wouldn't be suprised > if this recurred somewhere since they were popular and nobody really > noticed as they didn't run such an unusual config. > I have not made an inquiry with the vendor yet. I'm pretty sure I have done this with this very card in another mother board. I guess I need to dig that one up and verify it before I go much further. But it's much like you describe above. The data seems to just vanish. I can't see any way to use my v-metro to find out where it's going either. > Also does the board have a true IOMMU in the PCI-E side of the system ? > It's not a chipset I know. > That I don't know for sure but I thought they all did?? I'll verify that the VMIC card is in fact capable in that other MB before I do anything else. Thanks Mark -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
