Messages in this thread | | | Date | Mon, 12 Apr 2010 13:53:00 +0200 | From | Andi Kleen <> | Subject | Re: USB transfer_buffer allocations on 64bit systems |
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> Which is exactly what usb_buffer_alloc() does already. So at least for > x86 you say this is the right thing to do? However, we don't necessarily > need coherent memory on other platforms, which is why I hessitate to > enforce that type of memory for all transfer_buffer allocations.
Yes today it's faster at least.
Probably we should have better interfaces for this, but we don't.
> > > Or just use GFP_KERNEL and pci_map_* later. > > The USB core does this already, but at least on Pedro's machine, this > seems unsufficient. Unfortunately, I can't reproduce the issue yet, even > with more than 4GB of RAM installed.
Then something must be broken in Pedro's system and likely other drivers will also not work. I don't think it should be worked around in the USB layer.
-Andi -- ak@linux.intel.com -- Speaking for myself only.
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