linux-kernel - Re: [PATCH v6 2/2] clk: wpcm450: Add Nuvoton WPCM450 clock/reset controller driver

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Message-ID: <ZEBiuRH3DjVUO/Kp@probook>
Date:   Wed, 19 Apr 2023 23:52:57 +0200
From:   Jonathan Neuschäfer <j.neuschaefer@....net>
To:     Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc:     j.neuschaefer@....net, avifishman70@...il.com,
        benjaminfair@...gle.com, daniel.lezcano@...aro.org,
        devicetree@...r.kernel.org, krzk+dt@...nel.org,
        linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-watchdog@...r.kernel.org, linux@...ck-us.net,
        mturquette@...libre.com, openbmc@...ts.ozlabs.org,
        p.zabel@...gutronix.de, robh+dt@...nel.org, sboyd@...nel.org,
        tali.perry1@...il.com, tglx@...utronix.de, tmaimon77@...il.com,
        venture@...gle.com, wim@...ux-watchdog.org, yuenn@...gle.com
Subject: Re: [PATCH v6 2/2] clk: wpcm450: Add Nuvoton WPCM450 clock/reset
 controller driver

Hello Christophe,

On Sat, Apr 15, 2023 at 02:16:09PM +0200, Christophe JAILLET wrote:
> Le 15/04/2023 à 13:13, Jonathan Neuschäfer a écrit :
> > This driver implements the following features w.r.t. the clock and reset
> > controller in the WPCM450 SoC:
> > 
> > - It calculates the rates for all clocks managed by the clock controller
> > - It leaves the clock tree mostly unchanged, except that it enables/
> >    disables clock gates based on usage.
> > - It exposes the reset lines managed by the controller using the
> >    Generic Reset Controller subsystem
> > 
> > NOTE: If the driver and the corresponding devicetree node are present,
> >        the driver will disable "unused" clocks. This is problem until
> >        the clock relations are properly declared in the devicetree (in a
> >        later patch). Until then, the clk_ignore_unused kernel parameter
> >        can be used as a workaround.
> > 
> > Signed-off-by: Jonathan Neuschäfer <j.neuschaefer-hi6Y0CQ0nG0@...lic.gmane.org>
> > ---
[...]
> > +	// Enables/gates
> > +	for (i = 0; i < ARRAY_SIZE(clken_data); i++) {
> > +		const struct wpcm450_clken_data *data = &clken_data[i];
> > +
> > +		hw = clk_hw_register_gate_parent_data(NULL, data->name, &data->parent, data->flags,
> > +						      clk_base + REG_CLKEN, data->bitnum,
> > +						      data->flags, &wpcm450_clk_lock);
> 
> If an error occures in the 'for' loop or after it, should this be
> clk_hw_unregister_gate()'ed somewhere?

Ideally yes —

in this case, if the clock driver fails, the system is arguably in such
a bad state that there isn't much point in bothering.


> 
> CJ
> 
> > +		if (IS_ERR(hw)) {
> > +			pr_err("Failed to register gate: %pe\n", hw);
> > +			goto err_free;
> > +		}
> > +		clk_data->hws[data->bitnum] = hw;
> > +	}



Best regards,
Jonathan

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