linux-kernel - Re: [PATCH regression fix] misc: lis3lv02d_i2c: Fix regulators getting en-/dis-abled twice on suspend/resume

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Date: Tue, 27 Feb 2024 17:25:37 +0100
From: "Linux regression tracking (Thorsten Leemhuis)"
 <regressions@...mhuis.info>
To: Hans de Goede <hdegoede@...hat.com>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Arnd Bergmann <arnd@...db.de>, Eric Piel <eric.piel@...mplin-utc.net>,
 linux-kernel@...r.kernel.org, Paul Menzel <pmenzel@...gen.mpg.de>,
 stable@...r.kernel.org, regressions@...ts.linux.dev
Subject: Re: [PATCH regression fix] misc: lis3lv02d_i2c: Fix regulators
 getting en-/dis-abled twice on suspend/resume

On 20.02.24 20:00, Hans de Goede wrote:
> When not configured for wakeup lis3lv02d_i2c_suspend() will call
> lis3lv02d_poweroff() even if the device has already been turned off
> by the runtime-suspend handler and if configured for wakeup and
> the device is runtime-suspended at this point then it is not turned
> back on to serve as a wakeup source.
>
> [...]
>
> Fixes: b1b9f7a49440 ("misc: lis3lv02d_i2c: Add missing setting of the reg_ctrl callback")
> Reported-by: Paul Menzel <pmenzel@...gen.mpg.de>
> Closes: https://lore.kernel.org/regressions/5fc6da74-af0a-4aac-b4d5-a000b39a63a5@molgen.mpg.de/
> Cc: stable@...r.kernel.org
> Cc: regressions@...ts.linux.dev

Paul, did you maybe test this? I suppose Greg had no time to review this
yet due to all the CVE stuff and stable tree maintenance; but with a bit
of luck a "Tested-by" from your side might motivate him or somebody else
to look into this.

Ciao, Thorsten

> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
> ---
>  drivers/misc/lis3lv02d/lis3lv02d_i2c.c | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/misc/lis3lv02d/lis3lv02d_i2c.c b/drivers/misc/lis3lv02d/lis3lv02d_i2c.c
> index c6eb27d46cb0..15119584473c 100644
> --- a/drivers/misc/lis3lv02d/lis3lv02d_i2c.c
> +++ b/drivers/misc/lis3lv02d/lis3lv02d_i2c.c
> @@ -198,8 +198,14 @@ static int lis3lv02d_i2c_suspend(struct device *dev)
>  	struct i2c_client *client = to_i2c_client(dev);
>  	struct lis3lv02d *lis3 = i2c_get_clientdata(client);
>  
> -	if (!lis3->pdata || !lis3->pdata->wakeup_flags)
> +	/* Turn on for wakeup if turned off by runtime suspend */
> +	if (lis3->pdata && lis3->pdata->wakeup_flags) {
> +		if (pm_runtime_suspended(dev))
> +			lis3lv02d_poweron(lis3);
> +	/* For non wakeup turn off if not already turned off by runtime suspend */
> +	} else if (!pm_runtime_suspended(dev))
>  		lis3lv02d_poweroff(lis3);
> +
>  	return 0;
>  }
>  
> @@ -208,13 +214,12 @@ static int lis3lv02d_i2c_resume(struct device *dev)
>  	struct i2c_client *client = to_i2c_client(dev);
>  	struct lis3lv02d *lis3 = i2c_get_clientdata(client);
>  
> -	/*
> -	 * pm_runtime documentation says that devices should always
> -	 * be powered on at resume. Pm_runtime turns them off after system
> -	 * wide resume is complete.
> -	 */
> -	if (!lis3->pdata || !lis3->pdata->wakeup_flags ||
> -		pm_runtime_suspended(dev))
> +	/* Turn back off if turned on for wakeup and runtime suspended*/
> +	if (lis3->pdata && lis3->pdata->wakeup_flags) {
> +		if (pm_runtime_suspended(dev))
> +			lis3lv02d_poweroff(lis3);
> +	/* For non wakeup turn back on if not runtime suspended */
> +	} else if (!pm_runtime_suspended(dev))
>  		lis3lv02d_poweron(lis3);
>  
>  	return 0;