Instead of using literals, add some symbolic constants for the IRQ delay
timer calculation.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
---

Changes in v2:
- New

 drivers/net/ethernet/xilinx/xilinx_axienet.h      | 3 +++
 drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 7 ++-----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h
index d70cb62ecf29..5c0a21ef96a4 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -119,6 +119,9 @@
 #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 b065979db196..cf67d455da48 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));
 }
 
 /**
-- 
2.35.1.1320.gc452695387.dirty