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    SubjectRe: [RFC PATCHv3 1/4] drivers/otp: add initial support for OTP memory
    On Fri, Mar 25, 2011 at 18:55, Jamie Iles wrote:
    > On Fri, Mar 25, 2011 at 06:50:36PM -0400, Mike Frysinger wrote:
    >> On Fri, Mar 25, 2011 at 18:47, Jamie Iles wrote:
    >> > On Fri, Mar 25, 2011 at 05:58:05PM -0400, Mike Frysinger wrote:
    >> >> On Fri, Mar 25, 2011 at 13:14, Jamie Iles wrote:
    >> >> > +static unsigned long registered_otp_map[BITS_TO_LONGS(MAX_OTP_DEVICES)];
    >> >> > +static DEFINE_MUTEX(otp_register_mutex);
    >> >>
    >> >> do we really need this ?  if we let the minor number dictate
    >> >> availability, then we can increment until that errors/wraps, and we
    >> >> dont need to do any tracking ...
    >> >
    >> > OK, so it would be nice to get rid of this but afaict we still need to
    >> > do some accounting of available minor numbers in the range that we've
    >> > allocated.  We could do a simple increment % 255 for the minor number
    >> > but if OTP devices are removed at runtime then that may get fragmented
    >> > and we would need to do retries of device_register() which feels a bit
    >> > too easy to mess up.
    >> >
    >> > Certainly allocating one major number for OTP devices then allocating
    >> > the minors one by one would be much better than what I have now.
    >> >
    >> > We probably also want it so that if you remove the OTP device that has
    >> > had regions called otpaN then reinsert it they doesn't suddenly become
    >> > otpbN.
    >>
    >> yeah that's true.  guess i'll leave it be then ;).
    >
    > OK, but it still might be worth pruning it down to a single major number
    > or is that something worth doing later on if it becomes needed?

    i dont think we'll see an explosion of OTP devices where we have to
    worry about major # exhaustion. if that day comes, we'll worry about
    things then.

    as long as we stick to dynamic device numbers, we have the flexibility
    to screw around later.
    -mike
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