[PATCH v6] dma-engine: sun4i: Simplify error handling in probe()

From: Bence Csókás
Date: Mon Mar 24 2025 - 13:30:34 EST


Clean up error handling by using devm functions and dev_err_probe(). This
should make it easier to add new code, as we can eliminate the "goto
ladder" in sun4i_dma_probe().

Suggested-by: Chen-Yu Tsai <wens@xxxxxxxxxx>
Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Acked-by: Chen-Yu Tsai <wens@xxxxxxxx>
Signed-off-by: Bence Csókás <csokas.bence@xxxxxxxxx>
---

Notes:
Changes in v2:
* rebase on current next
Changes in v3:
* rebase on current next
* collect Jernej's tag
Changes in v4:
* rebase on current next
* collect Chen-Yu's tag
Changes in v5:
* reformat msg to 75 cols
* keep `\n`s in error messages
Changes in v6:
* remove redundant braces
* break lines to stay under 85 cols
* reword subject and message

drivers/dma/sun4i-dma.c | 46 ++++++++++++-----------------------------
1 file changed, 13 insertions(+), 33 deletions(-)

diff --git a/drivers/dma/sun4i-dma.c b/drivers/dma/sun4i-dma.c
index 24796aaaddfa..00d2fd38d17f 100644
--- a/drivers/dma/sun4i-dma.c
+++ b/drivers/dma/sun4i-dma.c
@@ -1249,11 +1249,10 @@ static int sun4i_dma_probe(struct platform_device *pdev)
if (priv->irq < 0)
return priv->irq;

- priv->clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(priv->clk)) {
- dev_err(&pdev->dev, "No clock specified\n");
- return PTR_ERR(priv->clk);
- }
+ priv->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
+ "Couldn't start the clock\n");

if (priv->cfg->has_reset) {
priv->rst = devm_reset_control_get_exclusive_deasserted(&pdev->dev, NULL);
@@ -1328,12 +1327,6 @@ static int sun4i_dma_probe(struct platform_device *pdev)
vchan_init(&vchan->vc, &priv->slave);
}

- ret = clk_prepare_enable(priv->clk);
- if (ret) {
- dev_err(&pdev->dev, "Couldn't enable the clock\n");
- return ret;
- }
-
/*
* Make sure the IRQs are all disabled and accounted for. The bootloader
* likes to leave these dirty
@@ -1343,33 +1336,23 @@ static int sun4i_dma_probe(struct platform_device *pdev)

ret = devm_request_irq(&pdev->dev, priv->irq, sun4i_dma_interrupt,
0, dev_name(&pdev->dev), priv);
- if (ret) {
- dev_err(&pdev->dev, "Cannot request IRQ\n");
- goto err_clk_disable;
- }
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Cannot request IRQ\n");

- ret = dma_async_device_register(&priv->slave);
- if (ret) {
- dev_warn(&pdev->dev, "Failed to register DMA engine device\n");
- goto err_clk_disable;
- }
+ ret = dmaenginem_async_device_register(&priv->slave);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "Failed to register DMA engine device\n");

ret = of_dma_controller_register(pdev->dev.of_node, sun4i_dma_of_xlate,
priv);
- if (ret) {
- dev_err(&pdev->dev, "of_dma_controller_register failed\n");
- goto err_dma_unregister;
- }
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "Failed to register translation function\n");

dev_dbg(&pdev->dev, "Successfully probed SUN4I_DMA\n");

return 0;
-
-err_dma_unregister:
- dma_async_device_unregister(&priv->slave);
-err_clk_disable:
- clk_disable_unprepare(priv->clk);
- return ret;
}

static void sun4i_dma_remove(struct platform_device *pdev)
@@ -1380,9 +1363,6 @@ static void sun4i_dma_remove(struct platform_device *pdev)
disable_irq(priv->irq);

of_dma_controller_free(pdev->dev.of_node);
- dma_async_device_unregister(&priv->slave);
-
- clk_disable_unprepare(priv->clk);
}

static struct sun4i_dma_config sun4i_a10_dma_cfg = {
--
2.49.0