Messages in this thread | | | Date | Tue, 1 Feb 2011 14:22:01 +0900 | Subject | Re: b44 driver causes panic when using swiotlb | From | FUJITA Tomonori <> |
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On Mon, 31 Jan 2011 21:22:23 -0600 Robert Hancock <hancockrwd@gmail.com> wrote:
> > Some ideas to implement something that works for such device were > > discussed. Seems that the conclusion is that it's doesn't worth making > > the common code complicated for such minor and insane devices. > > I don't think this is the only device that has sub-32-bit DMA > restrictions, this will just lead to a bunch of duplicated code.
Yeah, not only device but not many.
The block layer has the own bouncing mechanism. Some network drivers have the similar bouncing code. I don't know if there are other kinds of drivers that have the own bouncing code.
I thought that we can make mm/bounce.c (used for block drivers now) work any drivers without complicating it. We could make swiotlb to do but it's too complicated and it doesn't worth.
> In > particular, how is LPC DMA supposed to work?
LPC DMA can't do 32bit dma?
> At the very least we should be allowing the driver to deal with the > failure instead of panicing the system. Otherwise we are just leaving a > land mine for people to trip over.
Agreed. swiotlb shouldn't panic in this case. I'll take care of it.
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