Re: [PATCH] i2c: fix missing pm_runtime_put_sync in i2c_device_probe

From: Wolfram Sang <wsa@the-dreams.de>
To: Alain Volmat <alain.volmat@st.com>,
	Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: robh+dt@kernel.org, mark.rutland@arm.com,
	pierre-yves.mordret@st.com, mcoquelin.stm32@gmail.com,
	alexandre.torgue@st.com, linux-i2c@vger.kernel.org,
	devicetree@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, fabrice.gasnier@st.com
Subject: Re: [PATCH] i2c: fix missing pm_runtime_put_sync in i2c_device_probe
Date: Thu, 30 Apr 2020 18:35:03 +0200	[thread overview]
Message-ID: <20200430163503.GA15047@ninjato> (raw)
In-Reply-To: <1588261401-11914-1-git-send-email-alain.volmat@st.com>

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On Thu, Apr 30, 2020 at 05:43:21PM +0200, Alain Volmat wrote:
> In case of the I2C client exposes the flag I2C_CLIENT_HOST_NOTIFY,
> pm_runtime_get_sync is called in order to always keep active the
> adapter. However later on, pm_runtime_put_sync is never called
> within the function in case of an error. This commit add this
> error handling.
> 
> Fixes: 72bfcee11cf8 ("i2c: Prevent runtime suspend of adapter when Host Notify is required")

Adding the patch author to CC.

> Signed-off-by: Alain Volmat <alain.volmat@st.com>
> ---
>  drivers/i2c/i2c-core-base.c | 22 ++++++++++++++++------
>  1 file changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 139aea351ffb..2e4560671183 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -338,8 +338,10 @@ static int i2c_device_probe(struct device *dev)
>  		} else if (ACPI_COMPANION(dev)) {
>  			irq = i2c_acpi_get_irq(client);
>  		}
> -		if (irq == -EPROBE_DEFER)
> -			return irq;
> +		if (irq == -EPROBE_DEFER) {
> +			status = irq;
> +			goto put_sync_adapter;
> +		}
>  
>  		if (irq < 0)
>  			irq = 0;
> @@ -353,15 +355,19 @@ static int i2c_device_probe(struct device *dev)
>  	 */
>  	if (!driver->id_table &&
>  	    !i2c_acpi_match_device(dev->driver->acpi_match_table, client) &&
> -	    !i2c_of_match_device(dev->driver->of_match_table, client))
> -		return -ENODEV;
> +	    !i2c_of_match_device(dev->driver->of_match_table, client)) {
> +		status = -ENODEV;
> +		goto put_sync_adapter;
> +	}
>  
>  	if (client->flags & I2C_CLIENT_WAKE) {
>  		int wakeirq;
>  
>  		wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
> -		if (wakeirq == -EPROBE_DEFER)
> -			return wakeirq;
> +		if (wakeirq == -EPROBE_DEFER) {
> +			status = wakeirq;
> +			goto put_sync_adapter;
> +		}
>  
>  		device_init_wakeup(&client->dev, true);
>  
> @@ -408,6 +414,10 @@ static int i2c_device_probe(struct device *dev)
>  err_clear_wakeup_irq:
>  	dev_pm_clear_wake_irq(&client->dev);
>  	device_init_wakeup(&client->dev, false);
> +put_sync_adapter:
> +	if (client->flags & I2C_CLIENT_HOST_NOTIFY)
> +		pm_runtime_put_sync(&client->adapter->dev);
> +
>  	return status;
>  }
>  
> -- 
> 2.17.1
> 

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