Re: [PATCH v6 06/12] power: supply: smb347-charger: Make smb347_set_writable() IRQ-safe

From: Sebastian Reichel <sre@kernel.org>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: Thierry Reding <treding@nvidia.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Mark Brown <broonie@kernel.org>,
	Peter Chen <peter.chen@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Felipe Balbi <balbi@kernel.org>, David Heidelberg <david@ixit.cz>,
	devicetree@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-tegra@vger.kernel.org
Subject: Re: [PATCH v6 06/12] power: supply: smb347-charger: Make smb347_set_writable() IRQ-safe
Date: Fri, 6 Aug 2021 23:13:33 +0200	[thread overview]
Message-ID: <20210806211333.uylwmagnoas3lyl2@earth.universe> (raw)
In-Reply-To: <20210731173842.19643-7-digetx@gmail.com>

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Hi,

On Sat, Jul 31, 2021 at 08:38:36PM +0300, Dmitry Osipenko wrote:
> The smb347_set_writable() is used by interrupt handler and outside of it.
> The interrupt should be disabled when the function is used outside of
> interrupt handler in order to prevent racing with the interrupt context.
> Add new parameter to smb347_set_writable() that allows to disable IRQ.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>

-- Sebastian

>  drivers/power/supply/smb347-charger.c | 30 +++++++++++++++++++--------
>  1 file changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/power/supply/smb347-charger.c b/drivers/power/supply/smb347-charger.c
> index df240420f2de..db1378b41f80 100644
> --- a/drivers/power/supply/smb347-charger.c
> +++ b/drivers/power/supply/smb347-charger.c
> @@ -671,10 +671,22 @@ static int smb347_set_temp_limits(struct smb347_charger *smb)
>   *
>   * Returns %0 on success and negative errno in case of failure.
>   */
> -static int smb347_set_writable(struct smb347_charger *smb, bool writable)
> +static int smb347_set_writable(struct smb347_charger *smb, bool writable,
> +			       bool irq_toggle)
>  {
> -	return regmap_update_bits(smb->regmap, CMD_A, CMD_A_ALLOW_WRITE,
> -				  writable ? CMD_A_ALLOW_WRITE : 0);
> +	struct i2c_client *client = to_i2c_client(smb->dev);
> +	int ret;
> +
> +	if (writable && irq_toggle && !smb->irq_unsupported)
> +		disable_irq(client->irq);
> +
> +	ret = regmap_update_bits(smb->regmap, CMD_A, CMD_A_ALLOW_WRITE,
> +				 writable ? CMD_A_ALLOW_WRITE : 0);
> +
> +	if ((!writable || ret) && irq_toggle && !smb->irq_unsupported)
> +		enable_irq(client->irq);
> +
> +	return ret;
>  }
>  
>  static int smb347_hw_init(struct smb347_charger *smb)
> @@ -682,7 +694,7 @@ static int smb347_hw_init(struct smb347_charger *smb)
>  	unsigned int val;
>  	int ret;
>  
> -	ret = smb347_set_writable(smb, true);
> +	ret = smb347_set_writable(smb, true, false);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -758,7 +770,7 @@ static int smb347_hw_init(struct smb347_charger *smb)
>  	ret = smb347_start_stop_charging(smb);
>  
>  fail:
> -	smb347_set_writable(smb, false);
> +	smb347_set_writable(smb, false, false);
>  	return ret;
>  }
>  
> @@ -866,7 +878,7 @@ static int smb347_irq_set(struct smb347_charger *smb, bool enable)
>  	if (smb->irq_unsupported)
>  		return 0;
>  
> -	ret = smb347_set_writable(smb, true);
> +	ret = smb347_set_writable(smb, true, true);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -891,7 +903,7 @@ static int smb347_irq_set(struct smb347_charger *smb, bool enable)
>  	ret = regmap_update_bits(smb->regmap, CFG_PIN, CFG_PIN_EN_CHARGER_ERROR,
>  				 enable ? CFG_PIN_EN_CHARGER_ERROR : 0);
>  fail:
> -	smb347_set_writable(smb, false);
> +	smb347_set_writable(smb, false, true);
>  	return ret;
>  }
>  
> @@ -919,7 +931,7 @@ static int smb347_irq_init(struct smb347_charger *smb,
>  	if (!client->irq)
>  		return 0;
>  
> -	ret = smb347_set_writable(smb, true);
> +	ret = smb347_set_writable(smb, true, false);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -931,7 +943,7 @@ static int smb347_irq_init(struct smb347_charger *smb,
>  				 CFG_STAT_ACTIVE_HIGH | CFG_STAT_DISABLED,
>  				 CFG_STAT_DISABLED);
>  
> -	smb347_set_writable(smb, false);
> +	smb347_set_writable(smb, false, false);
>  
>  	if (ret < 0) {
>  		dev_warn(smb->dev, "failed to initialize IRQ: %d\n", ret);
> -- 
> 2.32.0
> 

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