If device_register() fails, call put_device() to drop the device
reference. Also, call device_unregister() if device_create_file()
fails.

Found by code review.

Fixes: dc6876a288cc ("sh: dma - convert sysdev_class to a regular subsystem")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn>
---
 arch/sh/drivers/dma/dma-sysfs.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/sh/drivers/dma/dma-sysfs.c b/arch/sh/drivers/dma/dma-sysfs.c
index 9f666280d80c..5695fd0a0cd7 100644
--- a/arch/sh/drivers/dma/dma-sysfs.c
+++ b/arch/sh/drivers/dma/dma-sysfs.c
@@ -134,8 +134,10 @@ int dma_create_sysfs_files(struct dma_channel *chan, struct dma_info *info)
 	dev->bus = &dma_subsys;
 
 	ret = device_register(dev);
-	if (ret)
+	if (ret) {
+		put_device(dev);
 		return ret;
+	}
 
 	ret |= device_create_file(dev, &dev_attr_dev_id);
 	ret |= device_create_file(dev, &dev_attr_count);
@@ -145,6 +147,7 @@ int dma_create_sysfs_files(struct dma_channel *chan, struct dma_info *info)
 
 	if (unlikely(ret)) {
 		dev_err(&info->pdev->dev, "Failed creating attrs\n");
+		device_unregister(dev);
 		return ret;
 	}
 
-- 
2.25.1

> If device_register() fails, call put_device() to drop the device
> reference. Also, call device_unregister() if device_create_file()
> fails.

See also once more:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.19-rc1#n659


You propose to complete the exception handling for two cases.
Is there a need to indicate such a detail in the summary phrase accordingly?

Regards,
Markus

Hi Markus,

On Sat, 2025-12-20 at 14:56 +0100, Markus Elfring wrote:
> > If device_register() fails, call put_device() to drop the device
> > reference. Also, call device_unregister() if device_create_file()
> > fails.
> 
> See also once more:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.19-rc1#n659
> 
> 
> You propose to complete the exception handling for two cases.
> Is there a need to indicate such a detail in the summary phrase accordingly?

Maybe I'm completely missing something here, but I find the description short
and reasonable. As the SH maintainer, I haven't started reviewing these patches
themselves yet, I definitely interested to understand what the problem is.

Thanks,
Adrian

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