On Thu, 15 Oct 2026 00:39:21 +0800 Zhang Tengfei <[email protected]> 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/[email protected]> > > Compile tested only. Applied to next-net
