Re: [patch 0/5] HW RNG cleanup & new drivers

[Jeff Garzik <jgarzik@pobox.com>]

Deepak Saxena wrote:
> This patch adds support to the kernel for some more HW RNG devices
> and cleans up the code a bit.  My basic goal was to keep the same
> user space interface as exists, but not have to reproduce all
> the same 100 lines of user space interface code across every new
> driver (as we currently do with watchdogs...)
> 
> The new code separates the HW specific driver from the user 
> interface code and just adds a few function pointers so that
> the two can talk to each other. I opted out of using a sysfs
> class and all that complication b/c there will be one and only
> one RNG device at a time on a given system.
> 
> I've added drivers for Intels' IXP4xx and for the TI OMAP and
> these have both been tested.

I would prefer to let this live in -mm at least for a little while. 
Confirmation from AMD, Intel and VIA owners would be really nice, too. 
AMD and Intel might be a little bit hard to find.  I think Peter Anvin 
had an Intel ICH w/ RNG at one time...


> There was some discussion on lkml on the subject of killing
> the in-kernel driver and moving the whole implementation to
> user space but that cannot be done as some SOCs (MPC85xx for
> example) have the RNG unit as part of a larger device that
> needs kernel space code to manage command descriptor rings
> and other such things. We also want to be able to suspend/resume
> the RNG devices (see OMAP driver) and that needs to be done as part
> of the kernel PM path.

None of this precludes having this stuff in userspace.

That said, I don't object to your code being an intermediate step.

	Jeff (hw_random author)