Re: [PATCH] clk: Add clk_parent entry in debugfs

From: Stephen Boyd <sboyd@kernel.org>
To: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Michael Turquette <mturquette@baylibre.com>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	"linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] clk: Add clk_parent entry in debugfs
Date: Fri, 07 Jun 2019 12:05:22 -0700	[thread overview]
Message-ID: <20190607190522.D276520868@mail.kernel.org> (raw)
In-Reply-To: <057720844e78e615e46de34a73b16ffaf7dbfc10.1558686047.git.leonard.crestez@nxp.com>

Quoting Leonard Crestez (2019-05-24 01:25:25)
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index aa51756fd4d6..94a93b07dd37 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3009,10 +3009,21 @@ static int possible_parents_show(struct seq_file *s, void *data)
>  
>         return 0;
>  }
>  DEFINE_SHOW_ATTRIBUTE(possible_parents);
>  
> +static int current_parent_show(struct seq_file *s, void *data)
> +{
> +       struct clk_core *core = s->private;
> +
> +       if (core->parent)
> +               seq_printf(s, "%s\n", core->parent->name);
> +
> +       return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(current_parent);

Looks OK.

> +
>  static int clk_duty_cycle_show(struct seq_file *s, void *data)
>  {
>         struct clk_core *core = s->private;
>         struct clk_duty *duty = &core->duty;
>  
> @@ -3040,10 +3051,11 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
>         debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
>         debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
>         debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
>         debugfs_create_file("clk_duty_cycle", 0444, root, core,
>                             &clk_duty_cycle_fops);
> +       debugfs_create_file("clk_parent", 0444, root, core, &current_parent_fops);

Shouldn't we skip creation of this file if core->num_parents == 0? So
put this under the if condition below?

>  
>         if (core->num_parents > 1)
>                 debugfs_create_file("clk_possible_parents", 0444, root, core,
>                                     &possible_parents_fops);
>  