linux-kernel - [PATCH 3/7] dma: mcf-edma: Add per-channel IRQ naming for debugging

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Message-Id: <20251124-dma-coldfire-v1-3-dc8f93185464@yoseli.org>
Date: Mon, 24 Nov 2025 13:50:24 +0100
From: Jean-Michel Hautbois <jeanmichel.hautbois@...eli.org>
To: Frank Li <Frank.Li@....com>, Vinod Koul <vkoul@...nel.org>
Cc: Greg Ungerer <gerg@...ux-m68k.org>, imx@...ts.linux.dev, 
 dmaengine@...r.kernel.org, linux-m68k@...ts.linux-m68k.org, 
 linux-kernel@...r.kernel.org, 
 Jean-Michel Hautbois <jeanmichel.hautbois@...eli.org>
Subject: [PATCH 3/7] dma: mcf-edma: Add per-channel IRQ naming for
 debugging

Add dynamic per-channel IRQ naming to make DMA interrupt identification
easier in /proc/interrupts and debugging tools.

Instead of all channels showing "eDMA", they now show:
- "eDMA-0" through "eDMA-15" for channels 0-15
- "eDMA-16" through "eDMA-55" for channels 16-55
- "eDMA-tx-56" for the shared channel 56-63 interrupt
- "eDMA-err" for the error interrupt

This aids debugging DMA issues by making it clear which channel's
interrupt is being serviced.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@...eli.org>
---
 drivers/dma/mcf-edma-main.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/mcf-edma-main.c b/drivers/dma/mcf-edma-main.c
index f95114829d8006fe4558169888ff38037d7610de..8a7c1787adb1f66f3b6729903635b072218afad1 100644
--- a/drivers/dma/mcf-edma-main.c
+++ b/drivers/dma/mcf-edma-main.c
@@ -81,8 +81,12 @@ static int mcf_edma_irq_init(struct platform_device *pdev,
 	if (!res)
 		return -1;
 
-	for (ret = 0, i = res->start; i <= res->end; ++i)
-		ret |= request_irq(i, mcf_edma_tx_handler, 0, "eDMA", mcf_edma);
+	for (ret = 0, i = res->start; i <= res->end; ++i) {
+		char *irq_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+						"eDMA-%d", i - res->start);
+
+		ret |= request_irq(i, mcf_edma_tx_handler, 0, irq_name, mcf_edma);
+	}
 	if (ret)
 		return ret;
 
@@ -91,15 +95,19 @@ static int mcf_edma_irq_init(struct platform_device *pdev,
 	if (!res)
 		return -1;
 
-	for (ret = 0, i = res->start; i <= res->end; ++i)
-		ret |= request_irq(i, mcf_edma_tx_handler, 0, "eDMA", mcf_edma);
+	for (ret = 0, i = res->start; i <= res->end; ++i) {
+		char *irq_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+						"eDMA-%d", 16 + i - res->start);
+
+		ret |= request_irq(i, mcf_edma_tx_handler, 0, irq_name, mcf_edma);
+	}
 	if (ret)
 		return ret;
 
 	ret = platform_get_irq_byname(pdev, "edma-tx-56-63");
 	if (ret != -ENXIO) {
 		ret = request_irq(ret, mcf_edma_tx_handler,
-				  0, "eDMA", mcf_edma);
+				  0, "eDMA-tx-56", mcf_edma);
 		if (ret)
 			return ret;
 	}
@@ -107,7 +115,7 @@ static int mcf_edma_irq_init(struct platform_device *pdev,
 	ret = platform_get_irq_byname(pdev, "edma-err");
 	if (ret != -ENXIO) {
 		ret = request_irq(ret, mcf_edma_err_handler,
-				  0, "eDMA", mcf_edma);
+				  0, "eDMA-err", mcf_edma);
 		if (ret)
 			return ret;
 	}

-- 
2.39.5