Hi Dan,

On 12/1/20 11:27 AM, Dan Carpenter wrote:

On Mon, Nov 30, 2020 at 11:20:05AM -0300, Helen Koike wrote:

quoted

Hi Dan,

Thank you for your patch.

On 11/30/20 9:53 AM, Dan Carpenter wrote:

quoted

The debugfs_create_dir() function never returns NULLs.  It's not supposed
to checked for errors in the normal case and there is no need to check
in this function so let's just delete this dead code.

Signed-off-by: Dan Carpenter <redacted>
---
 drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
index 9af137e4967f..68da1eed753d 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c

@@ -430,10 +430,6 @@ static void rkisp1_debug_init(struct rkisp1_device *rkisp1)
 	struct rkisp1_debug *debug = &rkisp1->debug;
 
 	debug->debugfs_dir = debugfs_create_dir(RKISP1_DRIVER_NAME, NULL);
-	if (!debug->debugfs_dir) {
-		dev_dbg(rkisp1->dev, "failed to create debugfs directory\n");
-		return;
-	}

I was taking a look at the debugfs_create_dir() code, and I saw it can
return ERR_PTR(), so ideally we should check for errors with IS_ERR() / PTR_ERR().

Debugfs functions aren't meant to be error checked in the normal case.
There are some drivers which dereference the dentry pointer so those
need to check it but that's not very common and isn't the case here.

right, I just saw the functions in inode.c already checks the parent with
IS_ERR(). the debugfs_create_*() function calls start_creating() which
already checks the parent.

ok, fair enough, I'll ack v2.

Regards,
Helen

I'm really sure this must be documented somewhere but I can't find it
at all.  :P  But look at commit 057e212eae72 ("media: usb: uvc: no need
to check return value of debugfs_create functions") for example.

regards,
dan carpenter

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel