cvs commit: src/sys/dev/if_ndis if_ndis.c

[Bill Paul]

wpaul       2004/04/20 19:29:28 PDT

  FreeBSD src repository

  Modified files:
    sys/dev/if_ndis      if_ndis.c 
  Log:
  Fix the problems people have been having with the Intel 2100B Centrino
  wireless ever since I added the new spinlock code. Previously, I added
  a special ndis_rxeof_serial() function to insure that when we receive
  a packet, we never end up calling the MiniportReturnPacket() routine
  until after the receive handler has finished. I set things up so that
  ndis_rxeof_serial() would only be used for serialized miniports since
  they depend on this property. Well, it turns out deserialized miniports
  depend on a similar property: you can't let MiniportReturnPacket() be
  called from the same context as the receive handler at all. The 2100B
  driver happens to use a single spinlock for all of its synchronization,
  and it tries to acquire it both while in MiniportHandleInterrupt() and
  in MiniportReturnPacket(), so if we call MiniportReturnPacket() from
  the MiniportHandleInterrupt() context, we will end up trying to acquire
  the spinlock recursively, which you can't do.
  
  To fix this, I made the ndis_rxeof_serial() handler the default. An
  alternate solution would be to make ndis_return_packet() submit
  the call to MiniportReturnPacket() to the NDIS task queue thread.
  I may do that in the future, after I've tested things a bit more.
  
  Revision  Changes    Path
  1.54      +19 -107   src/sys/dev/if_ndis/if_ndis.c