Commit 70dbd5b0 authored Nov 27, 2006 by Gerrit Renker Committed by David S. Miller Dec 02, 2006

[DCCP] ccid3: Remove redundant statements in ccid3_hc_tx_packet_sent



This patch removes a switch statement which is redundant since,
 * nothing is done in states TFRC_SSTATE_NO_SENT/TFRC_SSTATE_NO_FBACK
 * it is impossible that the function is called in the state TFRC_SSTATE_TERM, since
       --the function is called, in dccp_write_xmit, after ccid3_hc_tx_send_packet
       --if ccid3_hc_tx_send_packet is called in state TFRC_SSTATE_TERM, it returns
         -EINVAL, which means that ccid3_hc_tx_packet_sent will not be called
	 (compare dccp_write_xmit)
       --> therefore, this case is logically impossible
 * the remaining state is TFRC_SSTATE_FBACK which conditionally updates t_ipi, t_nom,
   and t_delta. This is a no-op, since
       --t_ipi only changes when feedback is received
       --however, when feedback arrives via ccid3_hc_tx_packet_recv, there is an identical
         code block which performs the same set of operations
       --performing the same set of operations again in ccid3_hc_tx_packet_sent therefore
         does not change anything, since between the time of receiving the last feedback
	 (and therefore update of t_ipi, t_nom, and t_delta), the value of t_ipi has not
	 changed
       --since t_ipi has not changed, the values of t_delta and t_nom also do not change,
         they depend fully on t_ipi

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

parent da335baf

net/dccp/ccids/ccid3.c

+0 −21

Original line number	Diff line number	Diff line
		@@ -384,27 +384,6 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
		} else
		ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n",
		dccp_role(sk), sk, dp->dccps_gss);

		switch (hctx->ccid3hctx_state) {
		case TFRC_SSTATE_NO_SENT:
		/* fall through */
		case TFRC_SSTATE_NO_FBACK:
		/* t_nom, t_ipi, delta do not change until feedback arrives */
		return;
		case TFRC_SSTATE_FBACK:
		if (len > 0) {
		timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
		hctx->ccid3hctx_t_ipi);
		ccid3_calc_new_t_ipi(hctx);
		ccid3_calc_new_delta(hctx);
		timeval_add_usecs(&hctx->ccid3hctx_t_nom,
		hctx->ccid3hctx_t_ipi);
		}
		break;
		case TFRC_SSTATE_TERM:
		DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);
		break;
		}
		}

		static void ccid3_hc_tx_packet_recv(struct sock sk, struct sk_buff skb)