[PATCH net 0/2] net: macb: Fix Ethernet malfunction on AMD Versal board after suspend

[PATCH net 0/2] net: macb: Fix Ethernet malfunction on AMD Versal board after suspend

[Kevin Hao]

Hi,

On Versal boards, the tx/rx queue pointer registers are cleared after suspend,
which causes Ethernet malfunction. This patch series addresses this issue by
reinitializing the tx/rx queue pointer registers and the rx ring.

---
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>

---
Kevin Hao (2):
      net: macb: Introduce gem_init_rx_ring()
      net: macb: Reinitialize tx/rx queue pointer registers and rx ring during resume

 drivers/net/ethernet/cadence/macb_main.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)
---
base-commit: f90aadf1c67c8b4969d1e5e6d4fd7227adb6e4d7
change-id: 20260311-macb-versal-e5493bbac09f

Best regards,
-- 
Kevin Hao <haokexin@gmail.com>

[PATCH net 1/2] net: macb: Introduce gem_init_rx_ring()

[Kevin Hao]

Extract the initialization code for the GEM RX ring into a new function.
This change will be utilized in a subsequent patch. No functional changes
are introduced.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 952aaf84757c20e94f3bbc98162a18330aa4cf73..67f7ecb05a7d6b8a5f49da588faafe1aa70d0d2b 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -2805,6 +2805,14 @@ static void macb_init_tieoff(struct macb *bp)
 	desc->ctrl = 0;
 }
 
+static void gem_init_rx_ring(struct macb_queue *queue)
+{
+	queue->rx_tail = 0;
+	queue->rx_prepared_head = 0;
+
+	gem_rx_refill(queue);
+}
+
 static void gem_init_rings(struct macb *bp)
 {
 	struct macb_queue *queue;
@@ -2822,10 +2830,7 @@ static void gem_init_rings(struct macb *bp)
 		queue->tx_head = 0;
 		queue->tx_tail = 0;
 
-		queue->rx_tail = 0;
-		queue->rx_prepared_head = 0;
-
-		gem_rx_refill(queue);
+		gem_init_rx_ring(queue);
 	}
 
 	macb_init_tieoff(bp);

-- 
2.53.0

[PATCH net 2/2] net: macb: Reinitialize tx/rx queue pointer registers and rx ring during resume

[Kevin Hao]

On certain platforms, such as AMD Versal boards, the tx/rx queue pointer
registers are cleared after suspend, and the rx queue pointer register
is also disabled during suspend if WOL is enabled. Previously, we assumed
that these registers would be restored by macb_mac_link_up(). However,
in commit bf9cf80cab81, macb_init_buffers() was moved from
macb_mac_link_up() to macb_open(). Therefore, we should call
macb_init_buffers() to reinitialize the tx/rx queue pointer registers
during resume.

Due to the reset of these two registers, we also need to adjust the
tx/rx rings accordingly. The tx ring will be handled by
gem_shuffle_tx_rings() in macb_mac_link_up(), so we only need to
initialize the rx ring here.

Fixes: bf9cf80cab81 ("net: macb: Fix tx/rx malfunction after phy link down and up")
Reported-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Tested-by: Quanyang Wang <quanyang.wang@windriver.com>
Cc: stable@vger.kernel.org
---
 drivers/net/ethernet/cadence/macb_main.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 67f7ecb05a7d6b8a5f49da588faafe1aa70d0d2b..100f478c0d30e4a91021a7da83f8f08606eca66e 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -6106,8 +6106,18 @@ static int __maybe_unused macb_resume(struct device *dev)
 		rtnl_unlock();
 	}
 
+	if (!(bp->caps & MACB_CAPS_MACB_IS_EMAC))
+		macb_init_buffers(bp);
+
 	for (q = 0, queue = bp->queues; q < bp->num_queues;
 	     ++q, ++queue) {
+		if (!(bp->caps & MACB_CAPS_MACB_IS_EMAC)) {
+			if (macb_is_gem(bp))
+				gem_init_rx_ring(queue);
+			else
+				macb_init_rx_ring(queue);
+		}
+
 		napi_enable(&queue->napi_rx);
 		napi_enable(&queue->napi_tx);
 	}

-- 
2.53.0

Re: [PATCH net 0/2] net: macb: Fix Ethernet malfunction on AMD Versal board after suspend

[Simon Horman]

On Thu, Mar 12, 2026 at 04:13:57PM +0800, Kevin Hao wrote:
> Hi,
> 
> On Versal boards, the tx/rx queue pointer registers are cleared after suspend,
> which causes Ethernet malfunction. This patch series addresses this issue by
> reinitializing the tx/rx queue pointer registers and the rx ring.
> 
> ---
> Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
> Cc: Andrew Lunn <andrew+netdev@lunn.ch>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> 
> ---
> Kevin Hao (2):
>       net: macb: Introduce gem_init_rx_ring()
>       net: macb: Reinitialize tx/rx queue pointer registers and rx ring during resume
> 
>  drivers/net/ethernet/cadence/macb_main.c | 23 +++++++++++++++++++----
>  1 file changed, 19 insertions(+), 4 deletions(-)

For the series,

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net 0/2] net: macb: Fix Ethernet malfunction on AMD Versal board after suspend

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 12 Mar 2026 16:13:57 +0800 you wrote:
> Hi,
> 
> On Versal boards, the tx/rx queue pointer registers are cleared after suspend,
> which causes Ethernet malfunction. This patch series addresses this issue by
> reinitializing the tx/rx queue pointer registers and the rx ring.
> 
> 
> [...]

Here is the summary with links:
  - [net,1/2] net: macb: Introduce gem_init_rx_ring()
    https://git.kernel.org/netdev/net/c/1a7124ecd655
  - [net,2/2] net: macb: Reinitialize tx/rx queue pointer registers and rx ring during resume
    https://git.kernel.org/netdev/net/c/718d0766ce4c

You are awesome, thank you!
-- 
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