[PATCH v2 0/3] net/txgbe: fix FDIR Rx packet buffer handling

[Stephen Hemminger]

On Thu, 15 Oct 2026 00:39:21 +0800
Zhang Tengfei <zhtfdev at gmail.com> wrote:

> 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. It also rejects a mode other than signature
> or perfect while parsing, which configuration does not implement, so
> validate and create fail the same way.
> 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.


Applied to next-net