[PATCH v2 2/6] ntb: Use consistent DMA attributes when freeing DMA mappings

Leon Romanovsky
2026-05-01T06:35:31Z

The counterpart of dma_alloc_attrs() is dma_free_attrs(), which must
receive the same DMA attributes used during allocation. The code
previously used dma_free_coherent(), which does not accept or apply any
DMA attributes.

Fixes: 061a785a114f ("ntb: Force physically contiguous allocation of rx ring buffers")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/ntb/ntb_transport.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 771eb7d9f4356..f59f926d4bfaa 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -766,8 +766,8 @@ static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
return;

ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
- dma_free_coherent(dma_dev, mw->alloc_size,
- mw->alloc_addr, mw->original_dma_addr);
+ dma_free_attrs(dma_dev, mw->alloc_size, mw->alloc_addr,
+ mw->original_dma_addr, DMA_ATTR_FORCE_CONTIGUOUS);
mw->xlat_size = 0;
mw->buff_size = 0;
mw->alloc_size = 0;
@@ -828,8 +828,8 @@ static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
return 0;

err:
- dma_free_coherent(ntb_dev, mw->alloc_size, alloc_addr, dma_addr);
-
+ dma_free_attrs(ntb_dev, mw->alloc_size, alloc_addr, dma_addr,
+ DMA_ATTR_FORCE_CONTIGUOUS);
return rc;
}

--
2.53.0