Messages in this thread | | | Date | Mon, 29 Mar 2010 11:17:54 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 1/3] resource: shared I/O region support |
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On 03/29/2010 11:06 AM, Jesse Barnes wrote: >> >> I have to question this approach a bit. >> >> I would much rather see this as a two-step process, where multiple >> devices request the same region with a "sharable" flag, and then have a >> mutex associated with the struct resource (perhaps we need an outer >> container called "struct muxed_resource" or some such.) >> >> What I *really* object to with this patch is that it inherently assumes >> that there is only one multiplexed resource in the entire system... but >> of course nowhere enforces that. > > Well that does keep it simple, and with just one user that's probably > best. > > But why not use the common bus driver method? Muxing at the resource > level only seems to solve part of the problem... It doesn't guarantee > for example that driver A does something to a shared region that breaks > driver B; it just makes sure they don't access the same region at the > same time. >
The common bus driver method is the obvious thing to do, but it would presumably be greatly helped by librarization.
-hpa
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