[PATCH v2 1/5] net: cadence: macb: Set upper 32bits of DMA ring buffer

[Nicolas Ferre]

On 22/08/2025 at 11:34, Stanimir Varbanov wrote:
> In case of rx queue reset and 64bit capable hardware, set the upper
> 32bits of DMA ring buffer address.
> 
> Cc: stable at vger.kernel.org # v4.6+
> Fixes: 9ba723b081a2 ("net: macb: remove BUG_ON() and reset the queue to handle RX errors")
> Credits-to: Phil Elwell <phil at raspberrypi.com>
> Credits-to: Jonathan Bell <jonathan at raspberrypi.com>
> Signed-off-by: Stanimir Varbanov <svarbanov at suse.de>
> Reviewed-by: Andrew Lunn <andrew at lunn.ch>

Looks good to me: thanks!
Acked-by: Nicolas Ferre <nicolas.ferre at microchip.com>

> ---
> v1 -> v2:
>   - Added credits.
>   - Use lower_32_bits() for RBQP register writes for consistency (Nicolas).
>   - Added Fixes tag.
> 
>   drivers/net/ethernet/cadence/macb_main.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index ce95fad8cedd..36717e7e5811 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -1634,7 +1634,11 @@ static int macb_rx(struct macb_queue *queue, struct napi_struct *napi,
>                  macb_writel(bp, NCR, ctrl & ~MACB_BIT(RE));
> 
>                  macb_init_rx_ring(queue);
> -               queue_writel(queue, RBQP, queue->rx_ring_dma);
> +               queue_writel(queue, RBQP, lower_32_bits(queue->rx_ring_dma));
> +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
> +               if (bp->hw_dma_cap & HW_DMA_CAP_64B)
> +                       macb_writel(bp, RBQPH, upper_32_bits(queue->rx_ring_dma));
> +#endif
> 
>                  macb_writel(bp, NCR, ctrl | MACB_BIT(RE));
> 
> --
> 2.47.0
>