cvs commit: src/sys/pci if_vr.c

[Pyun YongHyeon]

yongari     2007-10-12 03:41:54 UTC

  FreeBSD src repository

  Modified files:        (Branch: RELENG_7)
    sys/pci              if_vr.c 
  Log:
  MFC if_vr.c, 1.127 to RELENG_7:
    Not all VIA Rhine chips support 256 register space. So touching
    VR_STICKHW register would result in unexpected results on these
    hardwares. wpaul said the following for the issue.
  
      The vr_attach() routine unconditionally does this for all supported
      chips:
  
          /*
           * Windows may put the chip in suspend mode when it
           * shuts down. Be sure to kick it in the head to wake it
           * up again.
           */
          VR_CLRBIT(sc, VR_STICKHW, (VR_STICKHW_DS0|VR_STICKHW_DS1));
  
      The problem is, the VR_STICKHW register is not valid on all Rhine
      devices. The VT86C100A chip, which is present on the D-Link DFE-530TX
      boards, doesn't support power management, and its register space is
      only 128 bytes wide. The VR_STICKHW register offset falls outside this
      range. This may go unnoticed in most scenarios, but if you happen to have
      another PCI device in your system which is assigned the register
      space immediately after that of the Rhine, the vr(4) driver will
      incorrectly stomp it. In my case, the BIOS on my test board decided
      to put the register space for my PRO/100 ethernet board right next
      to the Rhine, and the Rhine driver ended up clobbering the IMR register
      of the PRO/100 device. (Long story short: the board kept locking up on
      boot. Took me the better part of the morning suss out why.)
  
      The strictly correct thing to do would be to check the PCI config space
      to make sure the device supports the power management capability and only
      write to the VR_STICKHW register if it does.
  
    Instead of inspecting chip revision numbers for the availability of
    VR_STICKHW register, check the existence of power management capability
    of the hardware as wpaul suggested.
  
  Reported by:    wpaul
  Suggested by:   wpaul
  OK'ed by:       jhb
  Approved by:    re (kensmith)
  
  Revision   Changes    Path
  1.126.2.1  +4 -1      src/sys/pci/if_vr.c