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Date:   Fri, 14 Jul 2023 13:00:38 +0300
From:   Serge Semin <fancer.lancer@gmail.com>
To:     Wang Ming <machel@vivo.com>
Cc:     Jon Mason <jdmason@kudzu.us>, Dave Jiang <dave.jiang@intel.com>,
        Allen Hubbe <allenbh@gmail.com>,
        Dan Carpenter <error27@gmail.com>,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>, ntb@lists.linux.dev,
        linux-kernel@vger.kernel.org, opensource.kernel@vivo.com,
        dan.carpenter@linaro.org
Subject: Re: [PATCH v3]  ntb: Remove error checking for debugfs_create_dir()
Message-ID: <ag2uziaj2mbsqryo6ss25w5s3ryenshoylraejtgp46gxce6hh@qcggqjnqheb5>
References: <20230713085621.3380-1-machel@vivo.com>
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In-Reply-To: <20230713085621.3380-1-machel@vivo.com>
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On Thu, Jul 13, 2023 at 04:56:06PM +0800, Wang Ming wrote:
> It is expected that most callers should _ignore_ the errors
> return by debugfs_create_dir() in tool_setup_dbgfs()
> 
> Signed-off-by: Wang Ming <machel@vivo.com>

The patch itself is correct for sure:
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>

As a side note IMO I would have converted the driver to successfully
probe an NTB device only if DebugFS is enabled and all the DebugFS-nodes
are successfully created. That's because the driver fully relies on
the DebugFS nodes to activate its functionality. Without them being
available it's absolutely useless. The way the test-driver is utilized
is demonstrated for instance in the NTB-test script:
tools/testing/selftests/ntb/ntb_test.sh .

* It concerns all the NTB test drivers...

-Serge(y)

> ---
>  drivers/ntb/test/ntb_tool.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
> index eeeb4b1c97d2..e0acc11d29ba 100644
> --- a/drivers/ntb/test/ntb_tool.c
> +++ b/drivers/ntb/test/ntb_tool.c
> @@ -1495,8 +1495,6 @@ static void tool_setup_dbgfs(struct tool_ctx *tc)
>  
>  	tc->dbgfs_dir = debugfs_create_dir(dev_name(&tc->ntb->dev),
>  					   tool_dbgfs_topdir);
> -	if (!tc->dbgfs_dir)
> -		return;
>  
>  	debugfs_create_file("port", 0600, tc->dbgfs_dir,
>  			    tc, &tool_port_fops);
> -- 
> 2.25.1
>