Re: [PATCH] thermal/drivers/sun8i: Fix some error handling paths in sun8i_ths_probe()

[Christophe JAILLET]

Le 14/05/2023 à 17:35, Ondřej Jirman a écrit :
> Hello Christophe,
>
> On Sun, May 14, 2023 at 05:21:35PM +0200, Christophe JAILLET wrote:
> > Should an error occur after calling sun8i_ths_resource_init() in the probe
> > function, some resources need to be released, as already done in the
> > .remove() function.
> >
> > Switch to the devm_clk_get_enabled() helper and add a new devm_action to
> > turn sun8i_ths_resource_init() into a fully managed function.
> >
> > This fixes the issue and removes some LoC at the same time.
> >
> > Fixes: dccc5c3b6f30 ("thermal/drivers/sun8i: Add thermal driver for H6/H5/H3/A64/A83T/R40")
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> > ---
> > This changes the order of the release functions, but should be fine.
> > ---
> >   drivers/thermal/sun8i_thermal.c | 43 +++++++++------------------------
> >   1 file changed, 12 insertions(+), 31 deletions(-)
> >
> > diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c
> > index 793ddce72132..8f4c29bc85aa 100644
> > --- a/drivers/thermal/sun8i_thermal.c
> > +++ b/drivers/thermal/sun8i_thermal.c
> > @@ -319,6 +319,11 @@ static int sun8i_ths_calibrate(struct ths_device *tmdev)
> >   	return ret;
> >   }
> >   
> > +static void sun8i_ths_reset_control_assert(void *data)
> > +{
> > +	reset_control_assert(data);
> > +}
> > +
> >   static int sun8i_ths_resource_init(struct ths_device *tmdev)
> >   {
> >   	struct device *dev = tmdev->dev;
> > @@ -339,13 +344,13 @@ static int sun8i_ths_resource_init(struct ths_device *tmdev)
> >   		if (IS_ERR(tmdev->reset))
> >   			return PTR_ERR(tmdev->reset);
> >   
> > -		tmdev->bus_clk = devm_clk_get(&pdev->dev, "bus");
> > +		tmdev->bus_clk = devm_clk_get_enabled(&pdev->dev, "bus");
> >   		if (IS_ERR(tmdev->bus_clk))
> >   			return PTR_ERR(tmdev->bus_clk);
> >   	}
> >   
> >   	if (tmdev->chip->has_mod_clk) {
> > -		tmdev->mod_clk = devm_clk_get(&pdev->dev, "mod");
> > +		tmdev->mod_clk = devm_clk_get_enabled(&pdev->dev, "mod");
>
> This changes the recommeded order of reset release/clock enable steps, eg. A64
> manual says:
>
> 	3.3.6.4. Gating and reset
>
> 	Make sure that the reset signal has been released before the release of
> 	module clock gating;

Ok, so moving reset_control_deassert() (and my proposed 
devm_add_action_or_reset()) just after devm_reset_control_get() should 
keep the expected order, right?

CJ

> kind regards,
> 	o.
>
> >   		if (IS_ERR(tmdev->mod_clk))
> >   			return PTR_ERR(tmdev->mod_clk);
> >   	}
> > @@ -354,32 +359,20 @@ static int sun8i_ths_resource_init(struct ths_device *tmdev)
> >   	if (ret)
> >   		return ret;
> >   
> > -	ret = clk_prepare_enable(tmdev->bus_clk);
> > +	ret = devm_add_action_or_reset(dev, sun8i_ths_reset_control_assert,
> > +				       tmdev->reset);
> >   	if (ret)
> > -		goto assert_reset;
> > +		return ret;
> >   
> >   	ret = clk_set_rate(tmdev->mod_clk, 24000000);
> >   	if (ret)
> > -		goto bus_disable;
> > -
> > -	ret = clk_prepare_enable(tmdev->mod_clk);
> > -	if (ret)
> > -		goto bus_disable;
> > +		return ret;
> >   
> >   	ret = sun8i_ths_calibrate(tmdev);
> >   	if (ret)
> > -		goto mod_disable;
> > +		return ret;
> >   
> >   	return 0;
> > -
> > -mod_disable:
> > -	clk_disable_unprepare(tmdev->mod_clk);
> > -bus_disable:
> > -	clk_disable_unprepare(tmdev->bus_clk);
> > -assert_reset:
> > -	reset_control_assert(tmdev->reset);
> > -
> > -	return ret;
> >   }
> >   
> >   static int sun8i_h3_thermal_init(struct ths_device *tmdev)
> > @@ -530,17 +523,6 @@ static int sun8i_ths_probe(struct platform_device *pdev)
> >   	return 0;
> >   }
> >   
> > -static int sun8i_ths_remove(struct platform_device *pdev)
> > -{
> > -	struct ths_device *tmdev = platform_get_drvdata(pdev);
> > -
> > -	clk_disable_unprepare(tmdev->mod_clk);
> > -	clk_disable_unprepare(tmdev->bus_clk);
> > -	reset_control_assert(tmdev->reset);
> > -
> > -	return 0;
> > -}
> > -
> >   static const struct ths_thermal_chip sun8i_a83t_ths = {
> >   	.sensor_num = 3,
> >   	.scale = 705,
> > @@ -642,7 +624,6 @@ MODULE_DEVICE_TABLE(of, of_ths_match);
> >   
> >   static struct platform_driver ths_driver = {
> >   	.probe = sun8i_ths_probe,
> > -	.remove = sun8i_ths_remove,
> >   	.driver = {
> >   		.name = "sun8i-thermal",
> >   		.of_match_table = of_ths_match,
> > --
> > 2.34.1