Re: [PATCH v3 03/14] dp8393x: Clean up endianness hacks

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 1/19/20 11:59 PM, Finn Thain wrote:
> According to the datasheet, section 3.4.4, "in 32-bit mode ... the SONIC
> always writes long words".
> 
> Therefore, use the same technique for the 'in_use' field that is used
> everywhere else, and write the full long word.
> 
> Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
> Tested-by: Laurent Vivier <laurent@vivier.eu>
> ---
> Changed since v1:
>   - Use existing 'address' variable rather than declare a new one.
> 
> Laurent tells me that a similar clean-up has been tried before.
> He referred me to commit c744cf7879 ("dp8393x: fix dp8393x_receive()")
> and commit 409b52bfe1 ("net/dp8393x: correctly reset in_use field").
> I believe the underlying issue has been fixed by the preceding patch,
> as this no longer breaks NetBSD 5.1.
> ---
>   hw/net/dp8393x.c | 17 ++++++-----------
>   1 file changed, 6 insertions(+), 11 deletions(-)
> 
> diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
> index b2fd44bc2f..2d2ace2549 100644
> --- a/hw/net/dp8393x.c
> +++ b/hw/net/dp8393x.c
> @@ -776,8 +776,6 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
>           return -1;
>       }
>   
> -    /* XXX: Check byte ordering */
> -
>       /* Check for EOL */
>       if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
>           /* Are we still in resource exhaustion? */
> @@ -847,15 +845,12 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
>           /* EOL detected */
>           s->regs[SONIC_ISR] |= SONIC_ISR_RDE;
>       } else {
> -        /* Clear in_use, but it is always 16bit wide */
> -        int offset = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
> -        if (s->big_endian && width == 2) {
> -            /* we need to adjust the offset of the 16bit field */
> -            offset += sizeof(uint16_t);
> -        }
> -        s->data[0] = 0;
> -        address_space_rw(&s->as, offset, MEMTXATTRS_UNSPECIFIED,
> -                         (uint8_t *)s->data, sizeof(uint16_t), 1);
> +        /* Clear in_use */
> +        size = sizeof(uint16_t) * width;
> +        address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
> +        dp8393x_put(s, width, 0, 0);
> +        address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
> +                         (uint8_t *)s->data, size, 1);
>           s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
>           s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
>           s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) | (((s->regs[SONIC_RSC] & 0x00ff) + 1) & 0x00ff);
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>