Merge branch 'net-xilinx-axienet-enable-adaptive-irq-coalescing-with-dim'

Sean Anderson says:

====================
net: xilinx: axienet: Report an error for bad coalesce settings
====================

Link: https://patch.msgid.link/20250116232954.2696930-1-sean.anderson@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 24 insertions, 13 deletions

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h
index d64b8abcf018..a3f4f3e42587 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -120,6 +120,9 @@
 #define XAXIDMA_IRQ_ERROR_MASK		0x00004000 /* Error interrupt */
 #define XAXIDMA_IRQ_ALL_MASK		0x00007000 /* All interrupts */
 
+/* Constant to convert delay counts to microseconds */
+#define XAXIDMA_DELAY_SCALE		(125ULL * USEC_PER_SEC)
+
 /* Default TX/RX Threshold and delay timer values for SGDMA mode */
 #define XAXIDMA_DFT_TX_THRESHOLD	24
 #define XAXIDMA_DFT_TX_USEC		50
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 07850ad331dd..9e7fa012e4fa 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -238,11 +238,8 @@ static u32 axienet_usec_to_timer(struct axienet_local *lp, u32 coalesce_usec)
 
 	/* 1 Timeout Interval = 125 * (clock period of SG clock) */
 	result = DIV64_U64_ROUND_CLOSEST((u64)coalesce_usec * clk_rate,
-					 (u64)125000000);
-	if (result > 255)
-		result = 255;
-
-	return result;
+					 XAXIDMA_DELAY_SCALE);
+	return min(result, FIELD_MAX(XAXIDMA_DELAY_MASK));
 }
 
 /**
@@ -2062,14 +2059,25 @@ axienet_ethtools_set_coalesce(struct net_device *ndev,
 		return -EINVAL;
 	}
 
-	if (ecoalesce->rx_max_coalesced_frames)
-		lp->coalesce_count_rx = ecoalesce->rx_max_coalesced_frames;
-	if (ecoalesce->rx_coalesce_usecs)
-		lp->coalesce_usec_rx = ecoalesce->rx_coalesce_usecs;
-	if (ecoalesce->tx_max_coalesced_frames)
-		lp->coalesce_count_tx = ecoalesce->tx_max_coalesced_frames;
-	if (ecoalesce->tx_coalesce_usecs)
-		lp->coalesce_usec_tx = ecoalesce->tx_coalesce_usecs;
+	if (!ecoalesce->rx_max_coalesced_frames ||
+	    !ecoalesce->tx_max_coalesced_frames) {
+		NL_SET_ERR_MSG(extack, "frames must be non-zero");
+		return -EINVAL;
+	}
+
+	if ((ecoalesce->rx_max_coalesced_frames > 1 &&
+	     !ecoalesce->rx_coalesce_usecs) ||
+	    (ecoalesce->tx_max_coalesced_frames > 1 &&
+	     !ecoalesce->tx_coalesce_usecs)) {
+		NL_SET_ERR_MSG(extack,
+			       "usecs must be non-zero when frames is greater than one");
+		return -EINVAL;
+	}
+
+	lp->coalesce_count_rx = ecoalesce->rx_max_coalesced_frames;
+	lp->coalesce_usec_rx = ecoalesce->rx_coalesce_usecs;
+	lp->coalesce_count_tx = ecoalesce->tx_max_coalesced_frames;
+	lp->coalesce_usec_tx = ecoalesce->tx_coalesce_usecs;
 
 	return 0;
 }