5.15-stable review patch. If anyone has any objections, please let me know.
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From: Ioana Ciornei ioana.ciornei@nxp.com
[ Upstream commit 902e81e679d86846a2404630d349709ad9372d0d ]
The blamed commit increased the needed headroom to account for alignment. This means that the size required to always align a Tx buffer was added inside the dpaa2_eth_needed_headroom() function. By doing that, a manual adjustment of the pointer passed to PTR_ALIGN() was no longer correct since the 'buffer_start' variable was already pointing to the start of the skb's memory.
The behavior of the dpaa2-eth driver without this patch was to drop frames on Tx even when the headroom was matching the 128 bytes necessary. Fix this by removing the manual adjust of 'buffer_start' from the PTR_MODE call.
Closes: https://lore.kernel.org/netdev/70f0dcd9-1906-4d13-82df-7bbbbe7194c6@app.fast... Fixes: f422abe3f23d ("dpaa2-eth: increase the needed headroom to account for alignment") Signed-off-by: Ioana Ciornei ioana.ciornei@nxp.com Tested-by: Mathew McBride matt@traverse.com.au Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20251016135807.360978-1-ioana.ciornei@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c index 7554cf37507df..0439bf465fa5b 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c @@ -1018,8 +1018,7 @@ static int dpaa2_eth_build_single_fd(struct dpaa2_eth_priv *priv, dma_addr_t addr;
buffer_start = skb->data - dpaa2_eth_needed_headroom(skb); - aligned_start = PTR_ALIGN(buffer_start - DPAA2_ETH_TX_BUF_ALIGN, - DPAA2_ETH_TX_BUF_ALIGN); + aligned_start = PTR_ALIGN(buffer_start, DPAA2_ETH_TX_BUF_ALIGN); if (aligned_start >= skb->head) buffer_start = aligned_start; else