USB DMA memory Allocation
Hans Petter Selasky
hps at bitfrost.no
Tue Aug 6 06:58:35 UTC 2013
On 08/06/13 03:24, aseem.jolly wrote:
> I don't want to play around with 'kern.maxbcache', can we actually allow
> driver to support 64 bit DMA?
> In future we can use a bootarg/sysctl to enable this support if someone
> comes across this issue else we will use 32 bit DMA allocations.
>
> I am willing to enable this support, please guide me.
>
Hi,
You can start with the EHCI driver, if you like. Download the EHCI PDF
from INTEL's site. Figure out all the 32-bit HIGH fields and put valid
data in them. For all 32-bit address there is a corresponding 32-bit
high field.
Thank you!
--HPS
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