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

From: Johannes Erdfelt (johannes@erdfelt.com)
Date: Fri Mar 09 2001 - 13:35:03 EST


On Fri, Mar 09, 2001, David S. Miller <davem@redhat.com> wrote:
> Manfred Spraul writes:
> > Do lots of drivers need the reverse mapping? It wasn't on my todo list
> > yet.
>
> I am against any API which provides this. It can be extremely
> expensive to do this on some architectures, and since the rest
> of the PCI dma API does not provide such an interface neither
> should the pool routines.

The API I hacked together for uhci.c didn't have this.

> Drivers can keep track of this kind of information themselves,
> and that is what I tell every driver author to do who complains
> of a lack of a "bus_to_virt()" type thing, it's just lazy
> programming.

Once I worked around not having a "bus_to_virt()" type thing I was happier
with the resulting code. I completely agree.

JE

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This archive was generated by hypermail 2b29 : Thu Mar 15 2001 - 21:00:10 EST