[Linux-stm32] [net-next] net: stmmac: handle endianness in dwmac4_get_timestamp

[Florian Fainelli]

On 2/14/19 9:26 AM, Alexandre Torgue wrote:
> GMAC IP is little-endian and used on several kind of CPU (big or little
> endian). Main callbacks functions of the stmmac drivers take care about
> it. It was not the case for dwmac4_get_timestamp function.

This is clearly a bugfix, so you should be targeting the 'net' tree and
provide a Fixes: tag so this can be backported to relevant stable kernels.

> 
> Signed-off-by: Alexandre Torgue <alexandre.torgue at st.com>
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
> index 20299f6..736e296 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
> @@ -241,15 +241,18 @@ static inline void dwmac4_get_timestamp(void *desc, u32 ats, u64 *ts)
>  static int dwmac4_rx_check_timestamp(void *desc)
>  {
>  	struct dma_desc *p = (struct dma_desc *)desc;
> +	unsigned int rdes0 = le32_to_cpu(p->des0);
> +	unsigned int rdes1 = le32_to_cpu(p->des1);
> +	unsigned int rdes3 = le32_to_cpu(p->des3);
>  	u32 own, ctxt;
>  	int ret = 1;
>  
> -	own = p->des3 & RDES3_OWN;
> -	ctxt = ((p->des3 & RDES3_CONTEXT_DESCRIPTOR)
> +	own = rdes3 & RDES3_OWN;
> +	ctxt = ((rdes3 & RDES3_CONTEXT_DESCRIPTOR)
>  		>> RDES3_CONTEXT_DESCRIPTOR_SHIFT);
>  
>  	if (likely(!own && ctxt)) {
> -		if ((p->des0 == 0xffffffff) && (p->des1 == 0xffffffff))
> +		if ((rdes0 == 0xffffffff) && (rdes1 == 0xffffffff))
>  			/* Corrupted value */
>  			ret = -EINVAL;
>  		else
> 


-- 
Florian