[PATCH 0/3] net/txgbe: fix FDIR Rx packet buffer handling

[Zhang Tengfei <zhtfdev@gmail.com>]

Enabling Flow Director reduces the Rx packet buffer 0 to reserve memory
for the filter table, but the size was computed from the current
register value and never restored when FDIR was no longer used. Since
the FDIR mode is reset when the last rule is removed, on flush, or when
enabling FDIR fails, the next rule enabled FDIR again and shrank the
buffer once more, until it underflowed. Validating a rule also enabled
FDIR.

Patch 1 computes the buffer size from the default packet buffer size,
which alone stops the repeated reduction.
Patch 2 stops enabling FDIR from flow validate and rolls back the mode
when the first rule fails.
Patch 3 disables FDIR and restores the buffer when no rule is left.

The same issue was fixed in ixgbe:
<https://patches.dpdk.org/project/dpdk/patch/20260927042545.45152-1-zhtfdev@gmail.com>

Compile tested only.

Zhang Tengfei (3):
  net/txgbe: fix Rx packet buffer size with flow director
  net/txgbe: do not enable flow director on flow validate
  net/txgbe: disable flow director when no rule is left

 drivers/net/txgbe/txgbe_ethdev.h |  1 +
 drivers/net/txgbe/txgbe_fdir.c   | 36 +++++++++++++++----
 drivers/net/txgbe/txgbe_flow.c   | 60 +++++++++++++++++---------------
 3 files changed, 62 insertions(+), 35 deletions(-)

-- 
2.53.0