FAILED: patch "[PATCH] net: wangxun: revert the adjustment of the IRQ vector" failed to apply to 6.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.15-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 <stable@vger.kernel.org>.

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-6.15.y
git checkout FETCH_HEAD
git cherry-pick -x e37546ad1f9b2c777d3a21d7e50ce265ee3dece8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025070625-walnut-bargraph-970b@gregkh' --subject-prefix 'PATCH 6.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From e37546ad1f9b2c777d3a21d7e50ce265ee3dece8 Mon Sep 17 00:00:00 2001
From: Jiawen Wu <jiawenwu@trustnetic.com>
Date: Tue, 1 Jul 2025 14:30:29 +0800
Subject: [PATCH] net: wangxun: revert the adjustment of the IRQ vector
 sequence

Due to hardware limitations of NGBE, queue IRQs can only be requested
on vector 0 to 7. When the number of queues is set to the maximum 8,
the PCI IRQ vectors are allocated from 0 to 8. The vector 0 is used by
MISC interrupt, and althrough the vector 8 is used by queue interrupt,
it is unable to receive packets. This will cause some packets to be
dropped when RSS is enabled and they are assigned to queue 8.

So revert the adjustment of the MISC IRQ location, to make it be the
last one in IRQ vectors.

Fixes: 937d46ecc5f9 ("net: wangxun: add ethtool_ops for channel number")
Cc: stable@vger.kernel.org
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Link: https://patch.msgid.link/20250701063030.59340-3-jiawenwu@trustnetic.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/wangxun/libwx/wx_lib.c b/drivers/net/ethernet/wangxun/libwx/wx_lib.c
index 59840ba9c1fe..835d60bd5fbc 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_lib.c
+++ b/drivers/net/ethernet/wangxun/libwx/wx_lib.c
@@ -1747,7 +1747,7 @@ static void wx_set_num_queues(struct wx *wx)
  */
 static int wx_acquire_msix_vectors(struct wx *wx)
 {
-	struct irq_affinity affd = { .pre_vectors = 1 };
+	struct irq_affinity affd = { .post_vectors = 1 };
 	int nvecs, i;
 
 	/* We start by asking for one vector per queue pair */
@@ -1784,16 +1784,17 @@ static int wx_acquire_msix_vectors(struct wx *wx)
 		return nvecs;
 	}
 
-	wx->msix_entry->entry = 0;
-	wx->msix_entry->vector = pci_irq_vector(wx->pdev, 0);
 	nvecs -= 1;
 	for (i = 0; i < nvecs; i++) {
 		wx->msix_q_entries[i].entry = i;
-		wx->msix_q_entries[i].vector = pci_irq_vector(wx->pdev, i + 1);
+		wx->msix_q_entries[i].vector = pci_irq_vector(wx->pdev, i);
 	}
 
 	wx->num_q_vectors = nvecs;
 
+	wx->msix_entry->entry = nvecs;
+	wx->msix_entry->vector = pci_irq_vector(wx->pdev, nvecs);
+
 	return 0;
 }
 
@@ -2300,8 +2301,6 @@ static void wx_set_ivar(struct wx *wx, s8 direction,
 		wr32(wx, WX_PX_MISC_IVAR, ivar);
 	} else {
 		/* tx or rx causes */
-		if (!(wx->mac.type == wx_mac_em && wx->num_vfs == 7))
-			msix_vector += 1; /* offset for queue vectors */
 		msix_vector |= WX_PX_IVAR_ALLOC_VAL;
 		index = ((16 * (queue & 1)) + (8 * direction));
 		ivar = rd32(wx, WX_PX_IVAR(queue >> 1));
@@ -2340,7 +2339,7 @@ void wx_write_eitr(struct wx_q_vector *q_vector)
 
 	itr_reg |= WX_PX_ITR_CNT_WDIS;
 
-	wr32(wx, WX_PX_ITR(v_idx + 1), itr_reg);
+	wr32(wx, WX_PX_ITR(v_idx), itr_reg);
 }
 
 /**
@@ -2393,9 +2392,9 @@ void wx_configure_vectors(struct wx *wx)
 		wx_write_eitr(q_vector);
 	}
 
-	wx_set_ivar(wx, -1, 0, 0);
+	wx_set_ivar(wx, -1, 0, v_idx);
 	if (pdev->msix_enabled)
-		wr32(wx, WX_PX_ITR(0), 1950);
+		wr32(wx, WX_PX_ITR(v_idx), 1950);
 }
 EXPORT_SYMBOL(wx_configure_vectors);
 
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_type.h b/drivers/net/ethernet/wangxun/libwx/wx_type.h
index 7730c9fc3e02..d392394791b3 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_type.h
+++ b/drivers/net/ethernet/wangxun/libwx/wx_type.h
@@ -1343,7 +1343,7 @@ struct wx {
 };
 
 #define WX_INTR_ALL (~0ULL)
-#define WX_INTR_Q(i) BIT((i) + 1)
+#define WX_INTR_Q(i) BIT((i))
 
 /* register operations */
 #define wr32(a, reg, value)	writel((value), ((a)->hw_addr + (reg)))
diff --git a/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c b/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
index b5022c49dc5e..68415a7ef12f 100644
--- a/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
+++ b/drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
@@ -161,7 +161,7 @@ static void ngbe_irq_enable(struct wx *wx, bool queues)
 	if (queues)
 		wx_intr_enable(wx, NGBE_INTR_ALL);
 	else
-		wx_intr_enable(wx, NGBE_INTR_MISC);
+		wx_intr_enable(wx, NGBE_INTR_MISC(wx));
 }
 
 /**
diff --git a/drivers/net/ethernet/wangxun/ngbe/ngbe_type.h b/drivers/net/ethernet/wangxun/ngbe/ngbe_type.h
index bb74263f0498..6eca6de475f7 100644
--- a/drivers/net/ethernet/wangxun/ngbe/ngbe_type.h
+++ b/drivers/net/ethernet/wangxun/ngbe/ngbe_type.h
@@ -87,7 +87,7 @@
 #define NGBE_PX_MISC_IC_TIMESYNC		BIT(11) /* time sync */
 
 #define NGBE_INTR_ALL				0x1FF
-#define NGBE_INTR_MISC				BIT(0)
+#define NGBE_INTR_MISC(A)			BIT((A)->num_q_vectors)
 
 #define NGBE_PHY_CONFIG(reg_offset)		(0x14000 + ((reg_offset) * 4))
 #define NGBE_CFG_LAN_SPEED			0x14440
diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c
index dc468053bdf8..3885283681ec 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_irq.c
@@ -31,7 +31,7 @@ void txgbe_irq_enable(struct wx *wx, bool queues)
 	wr32(wx, WX_PX_MISC_IEN, misc_ien);
 
 	/* unmask interrupt */
-	wx_intr_enable(wx, TXGBE_INTR_MISC);
+	wx_intr_enable(wx, TXGBE_INTR_MISC(wx));
 	if (queues)
 		wx_intr_enable(wx, TXGBE_INTR_QALL(wx));
 }
@@ -131,7 +131,7 @@ static irqreturn_t txgbe_misc_irq_handle(int irq, void *data)
 		txgbe->eicr = eicr;
 		if (eicr & TXGBE_PX_MISC_IC_VF_MBOX) {
 			wx_msg_task(txgbe->wx);
-			wx_intr_enable(wx, TXGBE_INTR_MISC);
+			wx_intr_enable(wx, TXGBE_INTR_MISC(wx));
 		}
 		return IRQ_WAKE_THREAD;
 	}
@@ -183,7 +183,7 @@ static irqreturn_t txgbe_misc_irq_thread_fn(int irq, void *data)
 		nhandled++;
 	}
 
-	wx_intr_enable(wx, TXGBE_INTR_MISC);
+	wx_intr_enable(wx, TXGBE_INTR_MISC(wx));
 	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
 }
 
diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h b/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h
index 42ec815159e8..41915d7dd372 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h
@@ -302,8 +302,8 @@ struct txgbe_fdir_filter {
 #define TXGBE_DEFAULT_RX_WORK           128
 #endif
 
-#define TXGBE_INTR_MISC       BIT(0)
-#define TXGBE_INTR_QALL(A)    GENMASK((A)->num_q_vectors, 1)
+#define TXGBE_INTR_MISC(A)    BIT((A)->num_q_vectors)
+#define TXGBE_INTR_QALL(A)    (TXGBE_INTR_MISC(A) - 1)
 
 #define TXGBE_MAX_EITR        GENMASK(11, 3)