From mboxrd@z Thu Jan 1 00:00:00 1970 From: Helen Koike Date: Tue, 01 Dec 2020 14:38:33 +0000 Subject: Re: [PATCH] media: rockchip: rkisp1: remove some dead code Message-Id: List-Id: References: <20201201142754.GI2767@kadam> In-Reply-To: <20201201142754.GI2767@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: Dafna Hirschfeld , Heiko Stuebner , kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org 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: >> Hi Dan, >> >> Thank you for your patch. >> >> On 11/30/20 9:53 AM, Dan Carpenter wrote: >>> 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 >>> --- >>> 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 >