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 f422abe3f23d483cf01f386819f26fb3fe0dbb2b ]
Increase the needed headroom to account for a 64 byte alignment restriction which, with this patch, we make mandatory on the Tx path. The case in which the amount of headroom needed is not available is already handled by the driver which instead sends a S/G frame with the first buffer only holding the SW and HW annotation areas.
Without this patch, we can empirically see data corruption happening between Tx and Tx confirmation which sometimes leads to the SW annotation area being overwritten.
Since this is an old IP where the hardware team cannot help to understand the underlying behavior, we make the Tx alignment mandatory for all frames to avoid the crash on Tx conf. Also, remove the comment that suggested that this is just an optimization.
This patch also sets the needed_headroom net device field to the usual value that the driver would need on the Tx path: - 64 bytes for the software annotation area - 64 bytes to account for a 64 byte aligned buffer address
Fixes: 6e2387e8f19e ("staging: fsl-dpaa2/eth: Add Freescale DPAA2 Ethernet driver") Closes: https://lore.kernel.org/netdev/aa784d0c-85eb-4e5d-968b-c8f74fa86be6@gin.de/ Signed-off-by: Ioana Ciornei ioana.ciornei@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 8 ++++---- drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c index c48d410936517..78040a09313ef 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c @@ -952,14 +952,12 @@ 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); - - /* If there's enough room to align the FD address, do it. - * It will help hardware optimize accesses. - */ aligned_start = PTR_ALIGN(buffer_start - DPAA2_ETH_TX_BUF_ALIGN, DPAA2_ETH_TX_BUF_ALIGN); if (aligned_start >= skb->head) buffer_start = aligned_start; + else + return -ENOMEM;
/* Store a backpointer to the skb at the beginning of the buffer * (in the private data area) such that we can release it @@ -4446,6 +4444,8 @@ static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev) if (err) goto err_dl_port_add;
+ net_dev->needed_headroom = DPAA2_ETH_SWA_SIZE + DPAA2_ETH_TX_BUF_ALIGN; + err = register_netdev(net_dev); if (err < 0) { dev_err(dev, "register_netdev() failed\n"); diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h index cdb623d5f2c1a..67fd926331fed 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h @@ -670,7 +670,7 @@ static inline bool dpaa2_eth_rx_pause_enabled(u64 link_options)
static inline unsigned int dpaa2_eth_needed_headroom(struct sk_buff *skb) { - unsigned int headroom = DPAA2_ETH_SWA_SIZE; + unsigned int headroom = DPAA2_ETH_SWA_SIZE + DPAA2_ETH_TX_BUF_ALIGN;
/* If we don't have an skb (e.g. XDP buffer), we only need space for * the software annotation area