[U-Boot] [PATCH v2] net/designware: Consecutive writes to the same register to be avoided
Amit Virdi
amit.virdi at st.com
Mon Jun 11 06:26:57 CEST 2012
On 6/8/2012 8:56 PM, Dinh Nguyen wrote:
> This commit is an add-on to f6c4191f. There are a few registers where
> consecutive writes to the same location should be avoided or have a delay.
>
> According to Synopsys, here is a list of the registers and bit(s) where
> consecutive writes should be avoided or a delay is required:
>
> DMA Registers:
> Register 0 Bit 7
> Register 6 All bits except for 24, 16-13, 2-1.
>
> GMAC Registers:
> Registers 0-3 All bits
> Registers 6-7 All bits
> Register 10 All bits
> Register 11 All bits except for 5-6.
> Registers 16-47 All bits
> Register 48 All bits except for 18-16, 14.
> Register 448 Bit 4.
> Register 459 Bits 0-3.
>
> Reviewd-by: Matthew Gerlach<mgerlach at altera.com>
> Signed-off-by: Dinh Nguyen<dinguyen at altera.com>
> ---
> drivers/net/designware.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/designware.c b/drivers/net/designware.c
> index e8e669b..980b92f 100644
> --- a/drivers/net/designware.c
> +++ b/drivers/net/designware.c
> @@ -163,8 +163,8 @@ static int dw_eth_init(struct eth_device *dev, bd_t *bis)
> writel(FIXEDBURST | PRIORXTX_41 | BURST_16,
> &dma_p->busmode);
>
> - writel(FLUSHTXFIFO | readl(&dma_p->opmode),&dma_p->opmode);
> - writel(STOREFORWARD | TXSECONDFRAME,&dma_p->opmode);
> + writel(readl(&dma_p->opmode) | FLUSHTXFIFO | STOREFORWARD |
> + TXSECONDFRAME,&dma_p->opmode);
>
> conf = FRAMEBURSTENABLE | DISABLERXOWN;
>
Acked-by: Amit Virdi <amit.virdi at st.com>
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