Server Management - Remote Server Management
1748134 Members
3453 Online
108758 Solutions
New Discussion

VSP flow control on DL380 Gen9/iLO4 and DL380 Gen10/iLO5

 
pjacobi
Senior Member

VSP flow control on DL380 Gen9/iLO4 and DL380 Gen10/iLO5

I am a developer for the 16550 UART serial port driver on a custom operating system.  The serial port driver appears to work correctly on several platforms.
 
When the UART driver is loaded on a DL380 Gen9 and Gen10 via the Virtual Serial Port, I have observer characters being lost when output.  This seems to be an indication of improper flow control.
 
The document, "Lights-Out Virtual Serial Port configuration and operation
HOWTO, 4th edition" notes that flow control problems have been reported with Linux.  The document states that VSP defaults to Hardware Flow Control and provides a Perl/XML script to change the default to Software Flow Control.
 
I've ran the Perl/XML script against DL380 Gen9/iLo4 and DL380 Gen10/iLO5 systems which have successfully communicated with iLO, but it returns the error,
 
<?xml version="1.0"?>
<RIBCL VERSION="2.23">
<RESPONSE
    STATUS="0x003C"
    MESSAGE='Feature not supported - VSP_SOFTWARE_FLOW_CONTROL'
     />
</RIBCL>
 
How can I enable Software Flow Control on iLO4/iLO5 VSP?
 
Are the any bits in the UART registers that would provide any indication that the UART is busy and to hold off on sending more output?
 
How can I obtain reliable output to the VSP without resorting to per character time delay loops in the driver?
 
 
Paul A. Jacobi
VMS Software Inc.
4 REPLIES 4
pjacobi
Senior Member

Re: VSP flow control on DL380 Gen9/iLO4 and DL380 Gen10/iLO5

It's been 2 weeks since this was posted.  Any response appreciated.

 

Paul A. Jacobi

VMS Software, Inc.

pjacobi
Senior Member

Re: VSP flow control on DL380 Gen9/iLO4 and DL380 Gen10/iLO5

Does the iLo 4/5 VSP support any type of flow control?

If yes, does the VSP support Hardware flow control or Software flow control?

If no, how can the VSP avoid dropping character?  Character loss will eventually occur without flow control.

 

Paul A. Jacobi

VMS Software, Inc.

pjacobi
Senior Member

Re: VSP flow control on DL380 Gen9/iLO4 and DL380 Gen10/iLO5

I have observed that repeatedly outputting the following character sequence sometimes causes the iLO VSP to drop characters.
 
Character sequence:
<CR><LF><CR><NUL>'$' '  '
 
Results:
$
$
$
 
$
$
 
$
 
etc.
 
When the <NUL> is removed from the sequence, the '$' character is always displayed.
 
All other serial ports ignore the <NUL> character, except for iLO VSP.  Why?
 
 
Paul A. Jacobi
VMS Software Inc.
 
pjacobi
Senior Member

Re: VSP flow control on DL380 Gen9/iLO4 and DL380 Gen10/iLO5

I updated Gen10 iLO5 to 2..63 and the problem with Null characters and flow control appears to have been resolved in the iLO firmware.

I can still reproduce the problem with a Gen9 iLO4 1.79.  When will Gen9 iLO get the fixes from Gen10 iLO for Null characters and flow control?

 

Paul A. Jacobi

VMS Software, Inc.