[U-Boot] [PATCH 03/51] net: dwc: Fix cache alignment issues

[Chin Liang See]

Hi Marek, 

On Sun, 2014-09-21 at 14:58 +0200, marex at denx.de wrote:
> Fix remaining cache alignment issues in the DWC Ethernet driver.
> Please note that the cache handling in the driver is making the
> code hideous and thus the next patch cleans that up. In order to
> make this change reviewable though, the cleanup is split from it.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Chin Liang See <clsee at altera.com>
> Cc: Dinh Nguyen <dinguyen at altera.com>
> Cc: Albert Aribaud <albert.u.boot at aribaud.net>
> Cc: Tom Rini <trini at ti.com>
> Cc: Wolfgang Denk <wd at denx.de>
> Cc: Pavel Machek <pavel at denx.de>
> Cc: Joe Hershberger <joe.hershberger at gmail.com>
> ---
>  drivers/net/designware.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/designware.c b/drivers/net/designware.c
> index 7186e3b..aaf146d 100644
> --- a/drivers/net/designware.c
> +++ b/drivers/net/designware.c
> @@ -303,7 +303,8 @@ static int dw_eth_send(struct eth_device *dev, void *packet, int length)
>  
>  	/* Flush data to be sent */
>  	flush_dcache_range((unsigned long)desc_p->dmamac_addr,
> -			   (unsigned long)desc_p->dmamac_addr + length);
> +			   (unsigned long)desc_p->dmamac_addr +
> +			   roundup(length, ARCH_DMA_MINALIGN));
>  
>  #if defined(CONFIG_DW_ALTDESCRIPTOR)
>  	desc_p->txrx_status |= DESC_TXSTS_TXFIRST | DESC_TXSTS_TXLAST;
> @@ -372,7 +373,8 @@ static int dw_eth_recv(struct eth_device *dev)
>  		/* Flush only status field - others weren't changed */
>  		flush_dcache_range((unsigned long)&desc_p->txrx_status,
>  				   (unsigned long)&desc_p->txrx_status +
> -				   sizeof(desc_p->txrx_status));
> +					roundup(sizeof(desc_p->txrx_status),
> +						ARCH_DMA_MINALIGN));
>  

Current flush_dcache_range will clean & invalidate the whole cache line
which contain the address specified by start and end. Hence I believe
the alignment is not needed. Wonder the existing code got issue?

Thanks
Chin Liang


>  		/* Test the wrap-around condition. */
>  		if (++desc_num >= CONFIG_RX_DESCR_NUM)