[PATCH net] net: hibmcge: fix page_pool DMA direction mismatch
From: Jijie Shao <shaojijie@huawei.com>
Date: 2026-08-20 12:44:02
Also in:
lkml
Subsystem:
hisilicon network hibmcge driver, hisilicon network subsystem driver, networking drivers, the rest · Maintainers:
Jijie Shao, Jian Shen, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Jian Shen <shenjian15@huawei.com>
The driver memsets the RX buffer page head to zero before
submitting it to hardware, then calls dma_sync_single_for_device()
with DMA_TO_DEVICE. This sync direction does not match the pool
dma_dir which is DMA_FROM_DEVICE, violating the DMA API contract
that the sync direction must match the mapping direction.
On swiotlb platforms the mismatch can cause incorrect bounce-buffer
behaviour, and CONFIG_DMA_API_DEBUG emits a warning.
Switch the page_pool dma_dir to DMA_BIDIRECTIONAL so that the
CPU-to-device memset sync becomes legal.
Fixes: c30595917585 ("net: hibmcge: add support for pagepool on rx")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
---
drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c
index 0ae314994676..3e6ae2aa0d4b 100644
--- a/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c
+++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c@@ -553,7 +553,7 @@ static int hbg_ring_page_pool_init(struct hbg_priv *priv, struct hbg_ring *ring) .nid = dev_to_node(&priv->pdev->dev), .dev = &priv->pdev->dev, .napi = &ring->napi, - .dma_dir = DMA_FROM_DEVICE, + .dma_dir = DMA_BIDIRECTIONAL, .offset = 0, .max_len = hbg_get_page_size(ring), };
base-commit: e2466392a0b8496000e12181cb1ee1535eb0da25 -- 2.33.0