[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <38c07228-639f-4082-b09a-ffe62fe14b71@molgen.mpg.de>
Date: Fri, 1 Mar 2024 12:50:07 +0100
From: Paul Menzel <pmenzel@...gen.mpg.de>
To: Hans de Goede <hdegoede@...hat.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Arnd Bergmann <arnd@...db.de>, Eric Piel <eric.piel@...mplin-utc.net>,
linux-kernel@...r.kernel.org, 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
Dear Hans,
Thank you for the patch.
Am 20.02.24 um 20:00 schrieb Hans de Goede:
> 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.
>
> Before commit b1b9f7a49440 ("misc: lis3lv02d_i2c: Add missing setting
> of the reg_ctrl callback"), lis3lv02d_poweroff() failed to disable
> the regulators which as a side effect made calling poweroff() twice ok.
>
> Now that poweroff() correctly disables the regulators, doing this twice
> triggers a WARN() in the regulator core:
>
> unbalanced disables for regulator-dummy
> WARNING: CPU: 1 PID: 92 at drivers/regulator/core.c:2999 _regulator_disable
> ...
>
> Fix lis3lv02d_i2c_suspend() to not call poweroff() a second time if
> already runtime-suspended and add a poweron() call when necessary to
> make wakeup work.
>
> lis3lv02d_i2c_resume() has similar issues, with an added weirness that
> it always powers on the device if it is runtime suspended, after which
> the first runtime-resume will call poweron() again, causing the enabled
> count for the regulator to increase by 1 every suspend/resume. These
> unbalanced regulator_enable() calls cause the regulator to never
> be turned off and trigger the following WARN() on driver unbind:
>
> WARNING: CPU: 1 PID: 1724 at drivers/regulator/core.c:2396 _regulator_put
>
> Fix this by making lis3lv02d_i2c_resume() mirror the new suspend().
>
> 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
> 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;
I applied this commit on top of Linus’ master branch, and successfully
tested with S0ix and ACPI S3, that the warning is gone.
Tested-by: Paul Menzel <pmenzel@...gen.mpg.de> # Dell XPS 15 7590
Looking at the diff, this also looks good. Thank you for writing the
helpful commit message.
Reviewed-by: Paul Menzel <pmenzel@...gen.mpg.de>
Thank you for addressing this so quickly, and sorry for the late reply.
Kind regards,
Paul
Powered by blists - more mailing lists