Page MenuHomeFreeBSD

e1000: correctly set isc_pause_frames only when XOFF increases
ClosedPublic

Authored by jacob.e.keller_intel.com on Tue, Oct 1, 11:44 PM.

Details

Summary

The e1000 driver sets the iflib shared context isc_pause_frames value to
the number of received xoff frames. This is done so that the iflib
watchdog timer won't trigger a Tx Hang due to pause frames.

Unfortunately, the function simply sets it to the value of the xoffrxc
counter. Once the device has received a single XOFF packet, the driver
always reports that we received pause frames. This will prevent the Tx
hang detection entirely from that point on.

Fix this by assigning isc_pause_frames to a non-zero value if we
received any XOFF packets in the last timer interval.

We could attempt to calculate the total number of received packets by
doing a subtraction, but the iflib stack only seems to check if
isc_pause_frames is non-zero.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>

Diff Detail

Repository
rS FreeBSD src repository
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

erj set the repository for this revision to rS FreeBSD src repository.
gallatin accepted this revision.Wed, Oct 9, 8:47 PM
This revision is now accepted and ready to land.Wed, Oct 9, 8:47 PM
This revision was automatically updated to reflect the committed changes.