Messages in this thread | | | Date | Mon, 28 Apr 2008 18:53:52 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH RFC] x86: Fix 64-bit DMA masks on VIA |
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* Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> > > > This untested patch is supposed to fix DMAing on some VIA > > > > boards. Currently the DMA subsystem returns an error, if the > > > > driver does tell that it supports a 64bit DMA mask. So the > > > > driver probing would fail in that case. > > > > > > The driver is broken then. It is supposed to retry with a small > > > mask on an error. Please fix the driver. > > > > I already added a workaround to the driver. Why do we need to > > workaround this in _every_ driver? (Note that _every_ driver > > supporting a 64bit mask is affected). Why not fix it in the DMA > > layer? > > Some hardware wants to know it can get a given DMA mask or failure. I > agree however that a "pci_prefer_64bit_dma(pdev)" function would be a > good patch for someone to submit tot he PCI layer code.
yes, and i suspect Michael is correct in suggesting that the majority of drivers would use that interface and would let the PCI layer handle the probing/fallback details. (Jesse Cc:-ed)
Ingo
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