[PATCH net] net: wan/fsl_ucc_hdlc: Fix dma_free_coherent() in uhdlc_memclean()

Subsystems: freescale quicc engine ucc hdlc driver, networking drivers, the rest

STALE216d

2 messages, 2 authors, 2026-02-05 · open the first message on its own page

[PATCH net] net: wan/fsl_ucc_hdlc: Fix dma_free_coherent() in uhdlc_memclean()

From: Thomas Fourier <hidden>
Date: 2026-02-04 16:32:14

The priv->rx_buffer and priv->dma_rx_addr are alloc'd together as
contiguous buffers in uhdlc_init() but freed as two buffers in
uhdlc_memclean().

Change the cleanup to only call dma_free_coherent() once on the whole
buffer.

Fixes: c19b6d246a35 ("drivers/net: support hdlc function for QE-UCC")
Cc: <redacted>
Signed-off-by: Thomas Fourier <redacted>
---
 drivers/net/wan/fsl_ucc_hdlc.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index f999798a5612..59cd861d13d6 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -790,19 +790,11 @@ static void uhdlc_memclean(struct ucc_hdlc_private *priv)
 
 	if (priv->rx_buffer) {
 		dma_free_coherent(priv->dev,
-				  RX_BD_RING_LEN * MAX_RX_BUF_LENGTH,
+				  (RX_BD_RING_LEN + TX_BD_RING_LEN) * MAX_RX_BUF_LENGTH,
 				  priv->rx_buffer, priv->dma_rx_addr);
 		priv->rx_buffer = NULL;
 		priv->dma_rx_addr = 0;
 	}
-
-	if (priv->tx_buffer) {
-		dma_free_coherent(priv->dev,
-				  TX_BD_RING_LEN * MAX_RX_BUF_LENGTH,
-				  priv->tx_buffer, priv->dma_tx_addr);
-		priv->tx_buffer = NULL;
-		priv->dma_tx_addr = 0;
-	}
 }
 
 static int uhdlc_close(struct net_device *dev)
-- 
2.43.0

Re: [PATCH net] net: wan/fsl_ucc_hdlc: Fix dma_free_coherent() in uhdlc_memclean()

From: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Date: 2026-02-05 06:54:45


Le 04/02/2026 à 17:25, Thomas Fourier a écrit :
[Vous ne recevez pas souvent de courriers de fourier.thomas@gmail.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]

The priv->rx_buffer and priv->dma_rx_addr are alloc'd together as
You mean priv->rx_buffer and priv->tx_buffer I guess.
quoted hunk
contiguous buffers in uhdlc_init() but freed as two buffers in
uhdlc_memclean().

Change the cleanup to only call dma_free_coherent() once on the whole
buffer.

Fixes: c19b6d246a35 ("drivers/net: support hdlc function for QE-UCC")
Cc: <redacted>
Signed-off-by: Thomas Fourier <redacted>
---
  drivers/net/wan/fsl_ucc_hdlc.c | 10 +---------
  1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index f999798a5612..59cd861d13d6 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -790,19 +790,11 @@ static void uhdlc_memclean(struct ucc_hdlc_private *priv)

         if (priv->rx_buffer) {
                 dma_free_coherent(priv->dev,
-                                 RX_BD_RING_LEN * MAX_RX_BUF_LENGTH,
+                                 (RX_BD_RING_LEN + TX_BD_RING_LEN) * MAX_RX_BUF_LENGTH,
                                   priv->rx_buffer, priv->dma_rx_addr);
                 priv->rx_buffer = NULL;
                 priv->dma_rx_addr = 0;
You also have to do:
		priv->tx_buffer = NULL;
		priv->dma_tx_addr = 0;


Which that and commit message fixed you can add Reviewed-by: Christophe 
Leroy (CS GROUP) [off-list ref]



         }
-
-       if (priv->tx_buffer) {
-               dma_free_coherent(priv->dev,
-                                 TX_BD_RING_LEN * MAX_RX_BUF_LENGTH,
-                                 priv->tx_buffer, priv->dma_tx_addr);
-               priv->tx_buffer = NULL;
-               priv->dma_tx_addr = 0;
-       }
  }

  static int uhdlc_close(struct net_device *dev)
--
2.43.0

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