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SubjectRe: [PATCH] wan/fsl_ucc_hdlc: Fix size used in dma_free_coherent()
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Le 07/10/2016 à 22:58, Christophe JAILLET a écrit :
> Size used with 'dma_alloc_coherent()' and 'dma_free_coherent()' should be
> consistent.
> Here, the size of a pointer is used in dma_alloc... and the size of the
> pointed structure is used in dma_free...
>
> This has been spotted with coccinelle, using the following script:
> ////////////////////
> @r@
> expression x0, x1, y0, y1, z0, z1, t0, t1, ret;
> @@
>
> * ret = dma_alloc_coherent(x0, y0, z0, t0);
> ...
> * dma_free_coherent(x1, y1, ret, t1);
>
>
> @script:python@
> y0 << r.y0;
> y1 << r.y1;
>
> @@
> if y1.find(y0) == -1:
> print "WARNING: sizes look different: '%s' vs '%s'" % (y0, y1)
> ////////////////////
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Untested

I don't think the error is in the dma_free_coherent() calls.

The issue is for me in the dma_alloc_coherent() call. This call is
supposed to allocate a table of buffer descriptors, not a table of
pointers to BDs.

Later in the code, this is used the following way:

iowrite16be(bd_status, &priv->rx_bd_base[i].status);

So it is the allocation which should be

priv->rx_bd_base = dma_alloc_coherent(priv->dev,
RX_BD_RING_LEN * sizeof(struct qe_bd),
&priv->dma_rx_bd, GFP_KERNEL);

Christophe

> ---
> drivers/net/wan/fsl_ucc_hdlc.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
> index 5fbf83d5aa57..65647533b401 100644
> --- a/drivers/net/wan/fsl_ucc_hdlc.c
> +++ b/drivers/net/wan/fsl_ucc_hdlc.c
> @@ -295,11 +295,11 @@ static int uhdlc_init(struct ucc_hdlc_private *priv)
> qe_muram_free(priv->ucc_pram_offset);
> free_tx_bd:
> dma_free_coherent(priv->dev,
> - TX_BD_RING_LEN * sizeof(struct qe_bd),
> + TX_BD_RING_LEN * sizeof(struct qe_bd *),
> priv->tx_bd_base, priv->dma_tx_bd);
> free_rx_bd:
> dma_free_coherent(priv->dev,
> - RX_BD_RING_LEN * sizeof(struct qe_bd),
> + RX_BD_RING_LEN * sizeof(struct qe_bd *),
> priv->rx_bd_base, priv->dma_rx_bd);
> free_uccf:
> ucc_fast_free(priv->uccf);
> @@ -688,7 +688,7 @@ static void uhdlc_memclean(struct ucc_hdlc_private *priv)
>
> if (priv->rx_bd_base) {
> dma_free_coherent(priv->dev,
> - RX_BD_RING_LEN * sizeof(struct qe_bd),
> + RX_BD_RING_LEN * sizeof(struct qe_bd *),
> priv->rx_bd_base, priv->dma_rx_bd);
>
> priv->rx_bd_base = NULL;
> @@ -697,7 +697,7 @@ static void uhdlc_memclean(struct ucc_hdlc_private *priv)
>
> if (priv->tx_bd_base) {
> dma_free_coherent(priv->dev,
> - TX_BD_RING_LEN * sizeof(struct qe_bd),
> + TX_BD_RING_LEN * sizeof(struct qe_bd *),
> priv->tx_bd_base, priv->dma_tx_bd);
>
> priv->tx_bd_base = NULL;
>

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