[linux-usb-devel] Re: SLAB vs. pci_alloc_xxx in usb-uhci patch

[David S. Miller]

Russell King writes:
 > A while ago, I looked at what was required to convert the OHCI driver
 > to pci_alloc_consistent, and it turns out that the current interface is
 > highly sub-optimal.  It looks good on the face of it, but it _really_
 > does need sub-page allocations to make sense for USB.
 > 
 > At the time, I didn't feel like creating a custom sub-allocator just
 > for USB, and since then I haven't had the inclination nor motivation
 > to go back to trying to get my USB mouse or iPAQ communicating via USB.
 > (I've not used this USB port for 3 years anyway).

Gerard Roudier wrote for the sym53c8xx driver the exact thing
UHCI/OHCI need for this.

I think people are pissing their pants over the pci_alloc_consistent
interface for no reason.  It gives PAGE<<order sized/aligned chunks
back to the caller at the request of Linus so that drivers did not
have to guess "is this 16-byte aligned..." etc.

Later,
David S. Miller
[EMAIL PROTECTED]

_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
http://lists.sourceforge.net/lists/listinfo/linux-usb-devel