cvs commit: src/sys/dev/mpt mpt.c mpt.h mpt_cam.c

[Scott Long]

scottl      2007-06-03 23:13:05 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/mpt          mpt.c mpt.h mpt_cam.c 
  Log:
  mpt.c:
  mpt.h:
          Add support for reading extended configuration pages.
  mpt_cam.c:
          Do a top level topology scan on the SAS controller.  If any SATA
          device are discovered in this scan, send a passthrough FIS to set
          the write cache.  This is controllable through the following
          tunable at boot:
  
          hw.mpt.enable_sata_wc:
                  -1 = Do not configure, use the controller default
                   0 = Disable the write cache
                   1 = Enable the write cache
  
          The default is -1.  This tunable is just a hack and may be
          deprecated in the future.
  
  Turning on the write cache alleviates the write performance problems with
  SATA that many people have observed.  It is not recommend for those who
  value data reliability!  I cannot stress this strongly enough.  However,
  it is useful in certain circumstances, and it brings the performence in line
  with what a generic SATA controller running under the FreeBSD ATA driver
  provides (and the ATA driver has had the WC enabled by default for years).
  
  Revision  Changes    Path
  1.42      +154 -29   src/sys/dev/mpt/mpt.c
  1.41      +55 -3     src/sys/dev/mpt/mpt.h
  1.57      +305 -0    src/sys/dev/mpt/mpt_cam.c