Comment 22 for bug 292214

Here is a better patch for the mga driver which doesn't require the changes to libpciaccess. This one eliminates the duplicate mappings and counts how many heads are using mapping to prevent unmapping too early. It also fixes a bug I found where the i2c monitor detection on the second head leaves mappings behind forever.

I think this is a reasonably good way to fix the problem and it works fine on my machine. I'm no expert on matrox cards or Xorg drivers though so, as before, use with caution.