Add missing dma_rmb() in airoha_qdma_rx_process routine to make sure the DMA read operations are completed when the NIC reports the processing on the current descriptor is done. Moreover, add missing READ_ONCE() in airoha_qdma_rx_process() for DMA descriptor control fields in order to avoid any compiler reordering. Fixes: 23020f0493270 ("net: airoha: Introduce ethernet support for EN7581 SoC") Signed-off-by: Lorenzo Bianconi --- Changes in v2: - Use msg1 in airoha_qdma_get_gdm_port() signature to avoid missing READ_ONCE(). - Link to v1: https://lore.kernel.org/r/20260402-airoha_qdma_rx_process-fix-reordering-v1-1-53278474f062@kernel.org --- drivers/net/ethernet/airoha/airoha_eth.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index 95ba99b89428..f1843bc5b991 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -581,10 +581,9 @@ static int airoha_qdma_fill_rx_queue(struct airoha_queue *q) return nframes; } -static int airoha_qdma_get_gdm_port(struct airoha_eth *eth, - struct airoha_qdma_desc *desc) +static int airoha_qdma_get_gdm_port(struct airoha_eth *eth, u32 msg1) { - u32 port, sport, msg1 = le32_to_cpu(desc->msg1); + u32 port, sport; sport = FIELD_GET(QDMA_ETH_RXMSG_SPORT_MASK, msg1); switch (sport) { @@ -612,15 +611,17 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) while (done < budget) { struct airoha_queue_entry *e = &q->entry[q->tail]; struct airoha_qdma_desc *desc = &q->desc[q->tail]; - u32 hash, reason, msg1 = le32_to_cpu(desc->msg1); - struct page *page = virt_to_head_page(e->buf); - u32 desc_ctrl = le32_to_cpu(desc->ctrl); + u32 hash, reason, msg1, desc_ctrl; struct airoha_gdm_port *port; int data_len, len, p; + struct page *page; + desc_ctrl = le32_to_cpu(READ_ONCE(desc->ctrl)); if (!(desc_ctrl & QDMA_DESC_DONE_MASK)) break; + dma_rmb(); + q->tail = (q->tail + 1) % q->ndesc; q->queued--; @@ -633,10 +634,12 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) if (!len || data_len < len) goto free_frag; - p = airoha_qdma_get_gdm_port(eth, desc); + msg1 = le32_to_cpu(READ_ONCE(desc->msg1)); + p = airoha_qdma_get_gdm_port(eth, msg1); if (p < 0 || !eth->ports[p]) goto free_frag; + page = virt_to_head_page(e->buf); port = eth->ports[p]; if (!q->skb) { /* first buffer */ q->skb = napi_build_skb(e->buf, q->buf_size); @@ -670,8 +673,8 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) * DMA descriptor. Report DSA tag to the DSA stack * via skb dst info. */ - u32 sptag = FIELD_GET(QDMA_ETH_RXMSG_SPTAG, - le32_to_cpu(desc->msg0)); + u32 msg0 = le32_to_cpu(READ_ONCE(desc->msg0)); + u32 sptag = FIELD_GET(QDMA_ETH_RXMSG_SPTAG, msg0); if (sptag < ARRAY_SIZE(port->dsa_meta) && port->dsa_meta[sptag]) --- base-commit: ec7067e661193403a7a00980bda8612db5954142 change-id: 20260402-airoha_qdma_rx_process-fix-reordering-722308255b65 Best regards, -- Lorenzo Bianconi