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Enable PCI bar reallocation by default.

Authored by jhb on Jan 25 2019, 6:40 PM.



When pci_realloc_bars was first added, the intention was to eventually
enable it by default, but it was left disabled to preserve existing
behavior. The setting is pretty conservative in that it does not
attempt to allocate resources for BARs that the BIOS/firmware leaves
disabled. It only attempts to reallocate resources for a BAR that the
firmware programmed during boot but that conflicts with another
resource during the kernel's device scan.

PR 221350 is an example of a machine that this knob fixes.

Test Plan
  • booted my test VM's, but they don't have conflicts

Diff Detail

rS FreeBSD src repository - subversion
Automatic diff as part of commit; lint not applicable.
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

I thought we did this years ago...
Now is a great time to do it. If there are issues, we'll find out in plenty of time to either (a) fix or (b) chicken out.

This revision is now accepted and ready to land.Feb 9 2019, 4:03 AM
This revision was automatically updated to reflect the committed changes.