| Message ID | Yv9O+9sxU7gAv3vM@fedora (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | iio: ad7292: Prevent regulator double disable | expand |
On Fri, 19 Aug 2022 11:51:07 +0300 Matti Vaittinen <mazziesaccount@gmail.com> wrote: > The ad7292 tries to add an devm_action for disabling a regulator at > device detach using devm_add_action_or_reset(). The > devm_add_action_or_reset() does call the release function should adding > action fail. The driver inspects the value returned by > devm_add_action_or_reset() and manually calls regulator_disable() if > adding the action has failed. This leads to double disable and messes > the enable count for regulator. > > Do not manually call disable if devm_add_action_or_reset() fails. > > Fixes: 506d2e317a0a ("iio: adc: Add driver support for AD7292") > Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> > Good spot. Applied to the fixes-togreg branch of iio.git and marked for stable. Jonathan > --- > > The bug was found during browsing the code. I don't have the hardware to > test this so reviewing and testing is highly appreciated. > --- > drivers/iio/adc/ad7292.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c > index 92c68d467c50..a2f9fda25ff3 100644 > --- a/drivers/iio/adc/ad7292.c > +++ b/drivers/iio/adc/ad7292.c > @@ -287,10 +287,8 @@ static int ad7292_probe(struct spi_device *spi) > > ret = devm_add_action_or_reset(&spi->dev, > ad7292_regulator_disable, st); > - if (ret) { > - regulator_disable(st->reg); > + if (ret) > return ret; > - } > > ret = regulator_get_voltage(st->reg); > if (ret < 0)
Hi Matti, thank you for this patch. On 08/19, Matti Vaittinen wrote: > The ad7292 tries to add an devm_action for disabling a regulator at > device detach using devm_add_action_or_reset(). The > devm_add_action_or_reset() does call the release function should adding > action fail. The driver inspects the value returned by > devm_add_action_or_reset() and manually calls regulator_disable() if > adding the action has failed. This leads to double disable and messes > the enable count for regulator. > That's correct. The regulator device even issued a message saying so fixed-supply: Underflow of regulator enable count Verified driver behavior on a raspberry pi with eval board. Thanks again for this fix. > Do not manually call disable if devm_add_action_or_reset() fails. > > Fixes: 506d2e317a0a ("iio: adc: Add driver support for AD7292") > Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> Jonathan, can we still add more tags to this patch? If so, please add mine Tested-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com> > > --- > > The bug was found during browsing the code. I don't have the hardware to > test this so reviewing and testing is highly appreciated. > --- > drivers/iio/adc/ad7292.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c > index 92c68d467c50..a2f9fda25ff3 100644 > --- a/drivers/iio/adc/ad7292.c > +++ b/drivers/iio/adc/ad7292.c > @@ -287,10 +287,8 @@ static int ad7292_probe(struct spi_device *spi) > > ret = devm_add_action_or_reset(&spi->dev, > ad7292_regulator_disable, st); > - if (ret) { > - regulator_disable(st->reg); > + if (ret) > return ret; > - } > > ret = regulator_get_voltage(st->reg); > if (ret < 0) > -- > 2.37.1 > > > -- > Matti Vaittinen, Linux device drivers > ROHM Semiconductors, Finland SWDC > Kiviharjunlenkki 1E > 90220 OULU > FINLAND > > ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ > Simon says - in Latin please. > ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ > Thanks to Simon Glass for the translation =]
diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c index 92c68d467c50..a2f9fda25ff3 100644 --- a/drivers/iio/adc/ad7292.c +++ b/drivers/iio/adc/ad7292.c @@ -287,10 +287,8 @@ static int ad7292_probe(struct spi_device *spi) ret = devm_add_action_or_reset(&spi->dev, ad7292_regulator_disable, st); - if (ret) { - regulator_disable(st->reg); + if (ret) return ret; - } ret = regulator_get_voltage(st->reg); if (ret < 0)
The ad7292 tries to add an devm_action for disabling a regulator at device detach using devm_add_action_or_reset(). The devm_add_action_or_reset() does call the release function should adding action fail. The driver inspects the value returned by devm_add_action_or_reset() and manually calls regulator_disable() if adding the action has failed. This leads to double disable and messes the enable count for regulator. Do not manually call disable if devm_add_action_or_reset() fails. Fixes: 506d2e317a0a ("iio: adc: Add driver support for AD7292") Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> --- The bug was found during browsing the code. I don't have the hardware to test this so reviewing and testing is highly appreciated. --- drivers/iio/adc/ad7292.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)