[PATCH net 0/3] net: stmmac: fix DMA allocation and IRQ failure cleanup

[Karl Mehltretter <kmehltretter@gmail.com>]

A DMA error-path review for the BeagleV Ahead found three bugs in the
common STMMAC code. Partial allocation can call buffer cleanup without
the metadata it indexes. A later TX allocation failure leaks the RX
resources allocated first. IRQ registration failure can release
descriptors and packet buffers while DMA remains active.

Patches 1 and 2 fix allocation cleanup. Patch 3 fixes the IRQ failure
unwind independently.

Testing:

- BeagleV Ahead, TH1520 DWMAC 3.70a: guarded baseline/fixed boots for RX
  and TX allocation failures and normal-open IRQ failure. Baseline runs
  reached the guarded unsafe boundaries. Fixed runs cleared the tracked
  resources and stopped DMA before cleanup.
- A matched follow-up applied the same RTL8211F-VD resume repair to all
  baseline and fixed kernels. At both 100 and 1000 Mbit/s, each variant
  passed eight close/open cycles (32 total), delay-register checks,
  pings and bidirectional 1 MiB SHA-256 transfers with no RX CRC or
  DMA-API errors.
- Native-XDP IRQ failure was exercised on the same board. The baseline
  reached IRQ unwind with DMA active and required a test-only rescue;
  the fixed kernel stopped DMA before unwind. Both reached descriptor
  cleanup with DMA inactive and no DMA-API errors.
- The physical native-XDP pair used CONFIG_BPF_JIT=n in both variants
  to bypass an independent RISC-V execmem Oops after the STMMAC unwind.
  The default configuration's XDP-open path remains covered by the QEMU
  fault-injection matrix.
- The exact combined code passed 24 of 24 checked 64 MiB transfers on
  fresh BeagleV Ahead boots with no DMA-API errors.
- QEMU orangepi-pc/dwmac-sun8i: 36 of 36 cold boots passed across the
  allocation and IRQ matrices, including XDP-open IRQ failure.
- The exact combined code cross-built the STMMAC objects and BeagleV
  Ahead DTB with a RISC-V defconfig and DWMAC_THEAD enabled.

The guards and fault-injection hooks are test-only and are not in this
series. The RTL8211F-VD repair is being submitted separately.

Based on 24a19b953e2a (Linux 7.3-rc7).

Karl Mehltretter (3):
  net: stmmac: handle partially allocated DMA queues
  net: stmmac: free RX resources when TX allocation fails
  net: stmmac: stop DMA when IRQ registration fails

 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 26 +++++++++++++++----
 1 file changed, 21 insertions(+), 5 deletions(-)


base-commit: 24a19b953e2a3d0ea5a8c4951a0ab8f32720c907
-- 
2.39.5 (Apple Git-154)