[PATCH v2 04/13] dmaengine: ste_dma40: Fix DMA registration unwind

[Linus Walleij <linusw@kernel.org>]

d40_dmaengine_init() registers DMAengine devices using devres-managed
unregister actions. If probe fails after one of those registrations, the
DMAengine devices stay visible until devres unwinds after d40_probe()
returns.

Release the DMAengine registration devres group before freeing the IRQ and
LCLA resources on the probe error path. Keep the managed registrations in
place on successful probe by removing only the temporary group markers.

Reported-by: sashiko-bot@kernel.org
Closes: https://lore.kernel.org/dmaengine/20260819225215.5EA2F1F000E9@smtp.kernel.org/
Assisted-by: Codex:gpt-5-5
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 drivers/dma/ste_dma40.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 145f7105218c..384c2f3805b0 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -3511,6 +3511,7 @@ static int __init d40_probe(struct platform_device *pdev)
 	struct d40_base *base;
 	struct resource *res;
 	struct resource res_lcpa;
+	void *dmaenginem_reg_group;
 	int num_reserved_chans;
 	u32 val;
 	int ret;
@@ -3638,20 +3639,29 @@ static int __init d40_probe(struct platform_device *pdev)
 
 	d40_hw_init(base);
 
+	dmaenginem_reg_group = devres_open_group(dev, NULL, GFP_KERNEL);
+	if (!dmaenginem_reg_group) {
+		ret = -ENOMEM;
+		goto destroy_cache;
+	}
+
 	ret = d40_dmaengine_init(base, num_reserved_chans);
 	if (ret)
-		goto destroy_cache;
+		goto release_dmaenginem;
 
 	ret = of_dma_controller_register(np, d40_xlate, NULL);
 	if (ret) {
 		dev_err(dev,
 			"could not register of_dma_controller\n");
-		goto destroy_cache;
+		goto release_dmaenginem;
 	}
+	devres_remove_group(dev, dmaenginem_reg_group);
 
 	dev_info(base->dev, "initialized\n");
 	return 0;
 
+ release_dmaenginem:
+	devres_release_group(dev, dmaenginem_reg_group);
  destroy_cache:
 	if (base->lcla_pool.dma_addr)
 		dma_unmap_single(base->dev, base->lcla_pool.dma_addr,

-- 
2.55.0