Re: [PATCH] net: macb: Add better comment for RXUBR handling

[Nicolas Ferre]

Le 14/05/2015 00:01, Nathan Sullivan a écrit :
> Describe the handler for RXUBR better with a new comment.
> 
> Signed-off-by: Nathan Sullivan <nathan.sullivan@xxxxxx>
> Reviewied-by: Josh Cartwright <joshc@xxxxxx>
> Reviewied-by: Ben Shelton <ben.shelton@xxxxxx>

Thanks Nathan: good that you've added this comment!

Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

> ---
>  drivers/net/ethernet/cadence/macb.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
> index 61aa570..5f10dfc 100644
> --- a/drivers/net/ethernet/cadence/macb.c
> +++ b/drivers/net/ethernet/cadence/macb.c
> @@ -1037,6 +1037,12 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
>  		 * add that if/when we get our hands on a full-blown MII PHY.
>  		 */
>  
> +		/* There is a hardware issue under heavy load where DMA can
> +		 * stop, this causes endless "used buffer descriptor read"
> +		 * interrupts but it can be cleared by re-enabling RX. See
> +		 * the at91 manual, section 41.3.1 or the Zynq manual
> +		 * section 16.7.4 for details.
> +		 */
>  		if (status & MACB_BIT(RXUBR)) {
>  			ctrl = macb_readl(bp, NCR);
>  			macb_writel(bp, NCR, ctrl & ~MACB_BIT(RE));
> 


-- 
Nicolas Ferre
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