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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>> </span></font><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Can anybody give a
definite answer if the CQ trigger has edge or level semantics, and what I need
to do to assure CQ entries are always processed without a delay? The docs for
ib_rearm_cq seem to say something different than the docs for ib_rearm_n_cq, so
the docs aren’t much help either.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>The semantics can vary based on HCA
model. In general the safe algorithm is:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>poll CQ until empty<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>rearm CQ<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>poll CQ until empty<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>The Mellanox HCA’s rearm CQ will
generate CQ interrupts for any still remaining on the CQ (hence not requiring
the 2<sup>nd</sup> poll loop). However the IBTA spec does not require
this behavior, so other HCAs may not implement it.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Todd Rimmer<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:navy'>Chief
Architect </span></font><font color=navy><span style='color:navy'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:navy'>QLogic System
Interconnect Group</span></font><font color=navy><span style='color:navy'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face="Courier New"><span
style='font-size:10.0pt;font-family:"Courier New";color:navy'>Voice:
610-233-4852 Fax: 610-233-4777<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><a href="mailto:Todd.Rimmer@QLogic.com"><font
face="Courier New"><span style='font-family:"Courier New"'>Todd.Rimmer@QLogic.com</span></font></a></span></font><font
size=2 color=navy face="Courier New"><span style='font-size:10.0pt;font-family:
"Courier New";color:navy'> <a href="http://www.QLogic.com">www.QLogic.com</a></span></font><font
color=navy><span style='color:navy'><o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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