[openib-general] [PATCH] opensm fails to find HCA if port is down.

[Hal Rosenstock]

Hi Ralph,

On Tue, 2006-01-10 at 13:31, Ralph Campbell wrote:
> If opensm is started with no arguments, the default algorithm
> for finding a port to bind to will skip ports which are present
> but the link is DOWN.  If there is only one port in the system,
> no port is selected and opensm tries the default HCA name "mthca0"
> which, if not present, confuses opensm and it exits.
> 
> The following patch changes the port selection so that the first
> active port is selected, and if none, the first non-disabled port.

This is close and headed in the right direction but has one property I'm
not too fond of: when there are no active ports, it does not prefer a
port whose physical state is link up over one in (say) polling (anything
other than link up) so the subnet may not come up when it could in that
case.

-- Hal

> Signed-off-by: Ralph Campbell <ralphc at pathscale.com>
> 
> Index: umad.c
> ===================================================================
> --- umad.c	(revision 4900)
> +++ umad.c	(working copy)
> @@ -207,9 +207,9 @@
>  }
>  
>  /*
> - * if *port > 0 checks ca[port] state. Otherwise set *port to
> + * if *port > 0, check ca[port] state. Otherwise set *port to
>   * the first port that is active, and if such is not found, to
> - * the first port that is (physically) up. Otherwise return -1;
> + * the first port that is not disabled.  Otherwise return -1;
>   */
>  static int
>  resolve_ca_port(char *ca_name, int *port)
> @@ -228,14 +228,14 @@
>  		return 1;
>  	}
>  
> -	if (*port > 0) {	/* user wants user gets */
> +	if (*port > 0) {	/* check only the port the user wants */
>  		if (*port > ca.numports)
>  			return -1;
>  		if (!ca.ports[*port])
>  			return -1;
>  		if (ca.ports[*port]->state == 4)
>  			return 1;
> -		if (ca.ports[*port]->phys_state == 5)
> +		if (ca.ports[*port]->phys_state != 3)
>  			return 0;
>  		return -1;
>  	}
> @@ -244,7 +244,7 @@
>  		DEBUG("checking port %d", i);
>  		if (!ca.ports[i])
>  			continue;
> -		if (up < 0 && ca.ports[i]->phys_state == 5)
> +		if (up < 0 && ca.ports[i]->phys_state != 3)
>  			up = *port = i;
>  		if (ca.ports[i]->state == 4) {
>  			active = *port = i;
> @@ -278,10 +278,11 @@
>  		return ca_name;
>  	}
>  		
> -	/* find first existing HCA with Active port */
> +	/* Get the list of CA names. */
>  	if ((n = umad_get_cas_names((void *)names, UMAD_CA_NAME_LEN)) < 0)
>  		return 0;
>  
> +	/* Find the first existing CA with an active port. */
>  	for (caidx = 0; caidx < n; caidx++) {
>  		TRACE("checking ca '%s'", names[caidx]);
>