3.0.2-testing: pci_set_dma_mask, pci_set_consistent_dma_mask(pci, 0x0fffffff) returns < 0 (ICE1712)

[Tom Hibbert <tom.xen@thoughtcrime.org.nz>]

Hi all,

I'm currently running on Ubuntu Dapper and xen 3.0 testing. I noticed my
sound card didnt work.

I looked in dmesg and found this:

Apr  9 17:49:29 phoenix kernel: [   27.490852] architecture does not
support 28bit PCI busmaster DMA

Grepping the kernel I came up with this, from sound/pci/ice1712/ice1712.c:

        /* check, if we can restrict PCI DMA transfers to 28 bits */
        if (pci_set_dma_mask(pci, 0x0fffffff) < 0 ||
            pci_set_consistent_dma_mask(pci, 0x0fffffff) < 0) {
                snd_printk(KERN_ERR "architecture does not support 28bit
PCI busmaster DMA\n");
                pci_disable_device(pci);
                return -ENXIO;
        }

I commented it out, and the module loaded but I got a burst of static
from the speakers. I suspect that this code is incompatible with Xen.

Why does Xen not allow the dom0 to set these parameters? My development
workstation is my main home box, and I like to have sound on it.

Thanks

Tom