[U-Boot] [PATCH v4 1/3] net: designware: fix descriptor layout and warnings on 64-bit archs

Marek Vasut
2016-04-17T09:56:58Z

On 04/17/2016 09:48 AM, Beniamino Galvani wrote:
> All members of the DMA descriptor must be 32-bit, even on 64-bit
> architectures: change the type to u32 to ensure this. Also, fix
> other warnings.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
> drivers/net/designware.c | 59 ++++++++++++++++++++++++++----------------------
> drivers/net/designware.h | 4 ++--
> 2 files changed, 34 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/net/designware.c b/drivers/net/designware.c
> index ca58f34..2eda461 100644
> --- a/drivers/net/designware.c
> +++ b/drivers/net/designware.c
> @@ -98,8 +98,8 @@ static void tx_descs_init(struct dw_eth_dev *priv)
>
> for (idx = 0; idx < CONFIG_TX_DESCR_NUM; idx++) {
> desc_p = &desc_table_p[idx];
> - desc_p->dmamac_addr = &txbuffs[idx * CONFIG_ETH_BUFSIZE];
> - desc_p->dmamac_next = &desc_table_p[idx + 1];
> + desc_p->dmamac_addr = (ulong)&txbuffs[idx * CONFIG_ETH_BUFSIZE];
> + desc_p->dmamac_next = (ulong)&desc_table_p[idx + 1];

Why don't you use u32 instead of ulong ? The u32 is well defined.
DTTO all over the place.

btw just curious, but what will happen if the descriptors get allocated
in area above 4GiB ? Will the code silently corrupt memory by discarding
the top bits in the descriptor pointer?

[...]

> diff --git a/drivers/net/designware.h b/drivers/net/designware.h
> index ed6344c..d48df7b 100644
> --- a/drivers/net/designware.h
> +++ b/drivers/net/designware.h
> @@ -110,8 +110,8 @@ struct eth_dma_regs {
> struct dmamacdescr {
> u32 txrx_status;
> u32 dmamac_cntl;
> - void *dmamac_addr;
> - struct dmamacdescr *dmamac_next;
> + u32 dmamac_addr;
> + u32 dmamac_next;
> } __aligned(ARCH_DMA_MINALIGN);
>
> /*
>

--
Best regards,
Marek Vasut