[net-next v6 3/4] net: ethernet: mtk_eth_soc: skip first IRQ if not used

[Frank Wunderlich <linux@fw-web.de>]

From: Frank Wunderlich <frank-w@public-files.de>

On SoCs with dedicated RX and TX interrupts (all except MT7621 and
MT7628) platform_get_irq() is called for the first IRQ (eth->irq[0])
but it is never used.
Skip the first IRQ and reduce the IRQ-count to 2.

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Simon Horman <horms@kernel.org>
---
v6:
- changed commit description a bit
- use MTK_FE_IRQ_SHARED instead of 0
v5:
- change commit title and description
v4:
- drop >2 condition as max is already 2 and drop the else continue
- update comment to explain which IRQs are taken in legacy way
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 12 ++++++++----
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  4 ++--
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index efffdd7e131e..67ba8927be46 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -3353,10 +3353,14 @@ static int mtk_get_irqs(struct platform_device *pdev, struct mtk_eth *eth)
 	 * the second is for TX, and the third is for RX.
 	 */
 	for (i = 0; i < MTK_FE_IRQ_NUM; i++) {
-		if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT) && i > 0)
-			eth->irq[i] = eth->irq[MTK_FE_IRQ_SHARED];
-		else
-			eth->irq[i] = platform_get_irq(pdev, i);
+		if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT)) {
+			if (i == MTK_FE_IRQ_SHARED)
+				eth->irq[MTK_FE_IRQ_SHARED] = platform_get_irq(pdev, i);
+			else
+				eth->irq[i] = eth->irq[MTK_FE_IRQ_SHARED];
+		} else {
+			eth->irq[i] = platform_get_irq(pdev, i + 1);
+		}
 
 		if (eth->irq[i] < 0) {
 			dev_err(&pdev->dev, "no IRQ%d resource found\n", i);
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 8cdf1317dff5..9261c0e13b59 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -643,8 +643,8 @@
 #define MTK_MAC_FSM(x)		(0x1010C + ((x) * 0x100))
 
 #define MTK_FE_IRQ_SHARED	0
-#define MTK_FE_IRQ_TX		1
-#define MTK_FE_IRQ_RX		2
+#define MTK_FE_IRQ_TX		0
+#define MTK_FE_IRQ_RX		1
 #define MTK_FE_IRQ_NUM		(MTK_FE_IRQ_RX + 1)
 
 struct mtk_rx_dma {
-- 
2.43.0