Re: [PATCH v2] iio: light: tsl2583: Fix module unloading

From: Shreeya Patel
Date: Thu Sep 08 2022 - 14:56:15 EST



On 28/08/22 22:03, Jonathan Cameron wrote:
On Fri, 26 Aug 2022 17:53:52 +0530
Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> wrote:

tsl2583 uses devm_iio_device_register() function and
calling iio_device_unregister() in remove breaks the
module unloading.
Fix this by using iio_device_register() instead of
devm_iio_device_register() function in probe.
Not sure why you are wrapping at 55 chars. I rewrapped this whilst applying.

Reworded it a little too as I was touching it anyway.

Applied to the fixes-togreg branch of iio.git.

Hi Jonathan,

I was wondering if this got picked by you. I don't see it in fixes-togreg that's why wanted to just confirm if you aren't looking for some extra changes in this.


Thanks
Shreeya Patel


Cc: stable@xxxxxxxxxxxxxxx
Fixes: 371894f5d1a0 ("iio: tsl2583: add runtime power management support")
I took a look at this patch and it introduces the issue I just pointed
out in replying to your v1 by dropping the
/* Make sure the chip is on */
Which was correct even with runtime pm because it covered the case of
runtime_pm being disabled. We probably need to bring that back as well,
perhaps as part of a cleanup patch taking this fully devm_

This driver has another issue for working if runtime PM isn't built into
the kernel which is that it checks the return of pm_runtime_put_autosuspend()
which calls

static inline int __pm_runtime_suspend(struct device *dev, int rpmflags)
{
return -ENOSYS;
}

I've been meaning to do an audit for drivers that have this problem for
a while, but not yet gotten to it.

An ideal IIO driver needs to work correctly whether or not CONFIG_PM is
enabled.

Jonathan


Signed-off-by: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx>
---
Changes in v2
- Use iio_device_register() instead of devm_iio_device_register()
- Add fixes and stable tags

drivers/iio/light/tsl2583.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c
index 82662dab87c0..94d75ec687c3 100644
--- a/drivers/iio/light/tsl2583.c
+++ b/drivers/iio/light/tsl2583.c
@@ -858,7 +858,7 @@ static int tsl2583_probe(struct i2c_client *clientp,
TSL2583_POWER_OFF_DELAY_MS);
pm_runtime_use_autosuspend(&clientp->dev);
- ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
+ ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&clientp->dev, "%s: iio registration failed\n",
__func__);