FAILED: patch "[PATCH] net: macb: Reinitialize tx/rx queue pointer registers and rx" failed to apply to 6.18-stable tree

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 718d0766ce4c7634ce62fa78b526ea7263487edd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026032059-clad-unselfish-9202@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 718d0766ce4c7634ce62fa78b526ea7263487edd Mon Sep 17 00:00:00 2001
From: Kevin Hao <[email protected]>
Date: Thu, 12 Mar 2026 16:13:59 +0800
Subject: [PATCH] net: macb: Reinitialize tx/rx queue pointer registers and rx
ring during resume

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.

index 4bdc7ccab730..033cff571904 100644
@@ -5952,8 +5952,18 @@ 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);
 	}

From: Kevin Hao <[email protected]>

[ Upstream commit 1a7124ecd655bcaf1845197fe416aa25cff4c3ea ]

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.

Stable-dep-of: 718d0766ce4c ("net: macb: Reinitialize tx/rx queue pointer registers and rx ring during resume")

---
 drivers/net/ethernet/cadence/macb_main.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

index 90550055c71c1..a20985f28f789 100644
@@ -2614,6 +2614,14 @@ 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;

@@ -2631,10 +2639,7 @@ 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);

2.51.0

From: Kevin Hao <[email protected]>

[ Upstream commit 718d0766ce4c7634ce62fa78b526ea7263487edd ]

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.

---
 drivers/net/ethernet/cadence/macb_main.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

index a20985f28f789..87fe529b740ed 100644
@@ -5856,8 +5856,18 @@ 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);
 	}

2.51.0