[syslinux] extlinux 6.03 IPMI SOL (serial-over-lan) console not responding to input

[Andrew J. Schorr]

On Mon, May 18, 2015 at 01:49:24PM -0400, Andrew J. Schorr via Syslinux wrote:
> The good news is that it still has the same problem as the Fedora version.
> If I attach a physical serial console, I am able to type at the boot 
> prompt.  But when using the IPMI serial-over-lan console, all of my
> input is ignored.  So the same problem exists in the official binaries.
> 
> I have seen this same behavior across three machines using two
> different motherboards: Intel S5500WB and Intel S5520UR.  And Ferenc Wagner
> says he has this problem with Fujitsu Primergy CX250 S2 servers.  So
> there appears to be a bad interaction with the serial support and IPMI SOL.
> This was all working fine in Fedora 19 extlinux 4.05.
> 
> Does anybody have any ideas on how to troubleshoot further?

Sorry for replying to my own post.  This behavior is very similar
to what happens under extlinux 4.05 when no flowcontrol flags are
specified.  When using IPMI SOL with 4.05, I found that I could not
interact with extlinux until I added the 0x003 flowcontrol bits to the
serial directive, like so:
   serial 0 115200 0x003
Is there any chance that the 6.03 version does not implement these flowcontrol
bits properly?  That would explain the behavior that I've seen...

Thanks,
Andy