Re: Default force_link_speed value in opensm configuration

Eli Dorfman (Voltaire)
2009-10-12T09:47:37Z

Ira Weiny wrote:
> On Tue, 06 Oct 2009 17:56:01 +0200
> "Eli Dorfman (Voltaire)" <dorfman.eli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
>> Hi,
>>
>> Is there a reason for setting default force_link_speed to 15 (set enabled as supported)
>> and not to 0 (don't modify PortInfo:LinkSpeedEnabled )?
>
> The thought was to enable all ports to the maximum supported by default. This
> was the behavior before this option was added so it was though to leave it
> alone by default.
>
> Is there a reason this should not happen? I guess since the Volume 2 spec
> says that the power on default for this is LinkSpeedSupported there is no
> reason to have the SM send these Set's. Perhaps there is broken hardware out
> there?

well actually there is a hardware that supports only 5.0Gbps (but reports 2.5 or 5.0 Gbps since there is no option for 5.0 only)
and powers on with enabled speed of 5.0Gbps only.
Setting the enabled speed to the supported speed will fail further negotiation (after link reset) since the device does not support 2.5Gbps.

So if the default for all other devices is enabled=supported then we can change the opensm configuration force_link_speed to 0.

Eli

>
> Ira
>
>
>> Thanks,
>> Eli
>> --