Re: DMA debug trace pointing to rtl8187

From: Greg KH
Date: Sat May 09 2009 - 15:34:05 EST


On Sat, May 09, 2009 at 12:29:27PM -0500, Larry Finger wrote:
> I think there is a second problem that John's fix does not treat. Although the
> buffer is removed from the stack, there is no assurance that the buffer obtained
> with kmalloc() is reachable by DMA. This case will be triggered if the USB
> adapter does 32-bit DMA and the system has more than 4 GB RAM.

Memory returned by kmalloc will always be able to be DMAable. If not,
we have lots of problems :)

thanks,

greg k-h
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