On Mon, Mar 10, 2003 at 10:52:17AM -0800, Randy.Dunlap wrote:
> On Mon, 10 Mar 2003 19:36:04 +0100 Oliver Neukum <[EMAIL PROTECTED]> wrote:
>
> | Am Montag, 10. März 2003 13:59 schrieb Duncan Sands:
> | > Hi all, must the transfer_buffer I provide with an urb be
> | > aligned on, say, a double-word boundary or something like
> | > that?
> |
> | The alignment requirements are specific to the hardware that happens
> | to be used. kmalloc() will return properly aligned memory.
>
> and only use kmalloc-ed memory (or get_free_page()), not local stack storage.
> This way there will be no DMA problems either.
FYI, in fact, this is explicitly stateed in DMA-mapping.txt under
"What memory is DMA'able?":
"...nor may you use kernel stack addresses for DMA."
Following all of the rules in that section will make those of us
working on non cache coherent processors very happy. :)
Regards,
--
Matt Porter
[EMAIL PROTECTED]
This is Linux Country. On a quiet night, you can hear Windows reboot.
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