[PATCH 3/4] Fix: Nokia BTS does not send RELease CONFirm message for local end release

[Holger Hans Peter Freyther]

On Thu, Dec 05, 2013 at 04:02:38PM +0100, Andreas Eversberg wrote:

> @@ -890,7 +892,18 @@ int rsl_release_request(struct gsm_lchan *lchan, uint8_t link_id,
>  	DEBUGP(DRLL, "%s RSL RLL RELEASE REQ (link_id=0x%02x, reason=%u)\n",
>  		gsm_lchan_name(lchan), link_id, release_mode);
>  
> -	return abis_rsl_sendmsg(msg);
> +	abis_rsl_sendmsg(msg);
> +
> +	/* Do not wait for Nokia BTS to send the confirm. */
> +	if (is_nokia_bts(lchan->ts->trx->bts)
> +	 && release_mode == RSL_REL_LOCAL_END) {
> +		DEBUGP(DRLL, "Do not wait for RELease CONFirm, because Nokia"
> +			" BTS does not send it.\n");
> +		lchan->sapis[link_id & 0x7] = LCHAN_SAPI_UNUSED;
> +		rsl_handle_release(lchan);


In addition to what I wrote yesterday. This is also violating the
principle of the least surprise and in fact breaks the error handling
release.


Before:
The "effect" rsl_release_request could be observed after the event loop
has been reached (only then we will parse the result from the BTS).

Your patch:
* RLL indication for the release is missing for the NokiaBTS (that is
  an issue and should be resolved by moving the sapi handling code out
  of the RSL_MT_REL_IND case into a method)
* You directly call rsl_handle_release and can get ahead of itself. This
  is a problem for:


	if (deact_sacch == SACCH_DEACTIVATE)
        	rsl_deact_sacch(lchan);
        rsl_release_sapis_from(lchan, 0, RSL_REL_LOCAL_END);
                        
        /* TODO: start T3109 now. */
        rsl_lchan_set_state(lchan, LCHAN_S_REL_ERR);

So with your change rsl_handle_release will be called when lchan->state
is not set to LCHAN_S_REL_ERR yet.

holger