[DCCP] ccid3: Two optimisations for sending rate recomputation
[DCCP] ccid3: Two optimisations for sending rate recomputation

This performs two optimisations for the recomputation of the sending rate.

1) Currently the target sending rate X_calc is recalculated whenever
	a) the nofeedback timer expires, or
	b) a feedback packet is received.
   In the (a) case, recomputing X_calc is redundant, since

    * the parameters p and RTT do not change in between the
      reception of feedback packets;

    * the parameter X_recv is either modified from received
      feedback or via the nofeedback timer;

    * a test (`p == 0') in the nofeedback timer avoids using
      a stale/undefined value of X_calc if p was previously 0.

2) The nofeedback timer now only recomputes a timestamp when p == 0.
   This is according to step (4) of [RFC 3448, 4.3] and avoids
   unnecessarily determining a timestamp.

A debug statement about not updating X is also removed - it helps very
little in debugging and just clutters the logs.

Signed-off-by: Gerrit Renker <3b97070d46ccd66422a8e7b83e6967ed84780538@erg.abdn.ac.uk>
Acked-by: Ian McDonald <2a05ad6b77741e349ccfbdf734f819b9b1d576cb@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@mandriva.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs