Subject: Re: [PATCH] net: wwan: qcom_bam_dmux: Fix missing pm_runtime_disable()

From: Stephan Gerhold <[email-masked]>
Date: Fri, 20 Sep 2024 14:45:53 +0200

On Fri, Sep 20, 2024 at 06:07:11PM +0800, Jinjie Ruan wrote:
> It's important to undo pm_runtime_use_autosuspend() with
> pm_runtime_dont_use_autosuspend() at driver exit time.
> 
> But the pm_runtime_disable() and pm_runtime_dont_use_autosuspend()
> is missing in the error path for bam_dmux_probe(). So add it.
> 
> Fixes: 21a0ffd9b38c ("net: wwan: Add Qualcomm BAM-DMUX WWAN network driver")
> Signed-off-by: Jinjie Ruan <[email-masked]>
> ---
>  drivers/net/wwan/qcom_bam_dmux.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wwan/qcom_bam_dmux.c b/drivers/net/wwan/qcom_bam_dmux.c
> index 26ca719fa0de..34a4e8095161 100644
> --- a/drivers/net/wwan/qcom_bam_dmux.c
> +++ b/drivers/net/wwan/qcom_bam_dmux.c
> @@ -823,17 +823,17 @@ static int bam_dmux_probe(struct platform_device *pdev)
>  	ret = devm_request_threaded_irq(dev, pc_ack_irq, NULL, bam_dmux_pc_ack_irq,
>  					IRQF_ONESHOT, NULL, dmux);
>  	if (ret)
> -		return ret;
> +		goto err_disable_pm;
>  
>  	ret = devm_request_threaded_irq(dev, dmux->pc_irq, NULL, bam_dmux_pc_irq,
>  					IRQF_ONESHOT, NULL, dmux);
>  	if (ret)
> -		return ret;
> +		goto err_disable_pm;
>  
>  	ret = irq_get_irqchip_state(dmux->pc_irq, IRQCHIP_STATE_LINE_LEVEL,
>  				    &dmux->pc_state);
>  	if (ret)
> -		return ret;
> +		goto err_disable_pm;
>  
>  	/* Check if remote finished initialization before us */
>  	if (dmux->pc_state) {
> @@ -844,6 +844,12 @@ static int bam_dmux_probe(struct platform_device *pdev)
>  	}
>  
>  	return 0;
> +
> +err_disable_pm:
> +	pm_runtime_disable(dev);
> +	pm_runtime_dont_use_autosuspend(dev);
> +	pm_runtime_set_suspended(dev);

Please drop the pm_runtime_set_suspended(dev); line, it should be
unneeded since runtime PM documentation says:

	the initial runtime PM status of all devices is ‘suspended’

Thanks,
Stephan