[PATCH v8 0/8] fix fwnode_irq_get[_byname()] returnvalue

[PATCH v8 0/8] fix fwnode_irq_get[_byname()] returnvalue

[Matti Vaittinen]

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The fwnode_irq_get() and the fwnode_irq_get_byname() may have returned
zero if mapping the IRQ fails. This contradicts the
fwnode_irq_get_byname() documentation. Furthermore, returning zero or
errno on error is unepected and can easily lead to problems
like:

int probe(foo)
{
...
	ret = fwnode_irq_get_byname(...);
	if (ret < 0)
		return ret;
...
}

or

int probe(foo)
{
...
	ret = fwnode_irq_get_byname(...);
	if (ret <= 0)
		return ret;
...
}

which are both likely to be wrong. First treats zero as successful call and
misses the IRQ mapping failure. Second returns zero from probe even though
it detects the IRQ mapping failure correvtly.

Thus the fwnode_irq_get() and the fwnode_irq_get_byname() were changed to
always return a negative errno upon failure.

https://lore.kernel.org/all/fb7241d3-d1d1-1c37-919b-488d6d007484@gmail.com/

This is a clean-up patch to adjust callers. Please note that callers
were audited based on v6.4-rc2:

fwnode_irq_get_byname():
drivers/i2c/i2c-smbus.c
drivers/iio/accel/adxl355_core.c
drivers/iio/accel/kionix-kx022a.c
drivers/iio/adc/ad4130.c
drivers/iio/adc/max11410.c
drivers/iio/addac/ad74115.c
drivers/iio/gyro/fxas21002c_core.c
drivers/iio/imu/adis16480.c
drivers/iio/imu/bmi160/bmi160_core.c
drivers/iio/imu/bmi160/bmi160_core.c

fwnode_irq_get():
drivers/gpio/gpio-dwapb.c
drivers/iio/chemical/scd30_serial.c
drivers/iio/proximity/mb1232.c
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
drivers/net/mdio/fwnode_mdio.c
drivers/pinctrl/pinctrl-ingenic.c
drivers/pinctrl/pinctrl-microchip-sgpio.c
drivers/pinctrl/pinctrl-pistachio.c

and it seems to me these calls will be Ok after this clean-up. The
i2c-smbus.c and kionix-kx022a.c will gain a functional change (bugfix?) as
after this patch the probe will return -EINVAL should the IRQ mapping fail.
The series will also adjust the return value check for zero to be omitted.

NOTES:

Changes are compile-tested only.

drivers/pinctrl/nuvoton/pinctrl-wpcm450.c
will also gain a functional change. The pinctrl-wpcm450.c change is easy
to see - after this series the device-tree mapping failures will be
handled as any other errors - probe will be aborted with -EINVAL. Other
feasible option could be treating other errors in IRQ getting same way
as the DT mapping failures - just silently skip the IRQ. Please see
comment in the respective patch.

drivers/iio/cdc/ad7150.c
Changed logic so that all the IRQ getting errors jump to the same
'no-IRQ' branch as the DT mapping error did.

Revision history:
v7 => v8:
 - drop ptach 1/N which was merged during 6.4 development.
 - rebase on top of the v6.5-rc4.
v6 => v7:
 - re-ordered patches per subsystem
 - mvpp2 - added a patch for not shadowing the return value
v5 => v6:
 - iio: cdc: ad7150 - never abort probe if IRQ getting fails
v4 => v5:
 - Fix subject lines for mvpp2 and wpcm450
 - drop unnecessary irqno assignment from mb1232
 - add back the drivers/i2c/i2c-smbus.c change which was accidentally
   dropped during v3 => v4 work
v3 => v4:
 - Change also the fwnode_irq_get() as was suggested by Jonathan.
Changelog v2 => v3:
 - rebase/resend/add kx022a fix.
Changelog v1 => v2:
 - minor styling

---

Matti Vaittinen (8):
  iio: mb1232: relax return value check for IRQ get
  iio: cdc: ad7150: relax return value check for IRQ get
  pinctrl: wpcm450: relax return value check for IRQ get
  pinctrl: ingenic: relax return value check for IRQ get
  pinctrl: pistachio: relax return value check for IRQ get
  i2c: i2c-smbus: fwnode_irq_get_byname() return value fix
  net-next: mvpp2: relax return value check for IRQ get
  net-next: mvpp2: don't shadow error

 drivers/i2c/i2c-smbus.c                         |  2 +-
 drivers/iio/cdc/ad7150.c                        | 10 +++++-----
 drivers/iio/proximity/mb1232.c                  |  7 ++-----
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 12 ++++++------
 drivers/pinctrl/nuvoton/pinctrl-wpcm450.c       |  2 --
 drivers/pinctrl/pinctrl-ingenic.c               |  2 --
 drivers/pinctrl/pinctrl-pistachio.c             |  6 ------
 7 files changed, 14 insertions(+), 27 deletions(-)


base-commit: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4
-- 
2.40.1


-- 
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 =] 

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[PATCH v8 1/8] iio: mb1232: relax return value check for IRQ get

[Matti Vaittinen]

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fwnode_irq_get() was changed to not return 0 anymore.

Drop check for return value 0.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

---
Revsion history:
v5 =>:
- No changes
v4 => v5:
 - drop unnecessary data->irqnr = -1 assignment

The patch changing the fwnode_irq_get() got merged during 5.4:
https://lore.kernel.org/all/fb7241d3-d1d1-1c37-919b-488d6d007484@gmail.com/
This is a clean-up as agreed.
---
 drivers/iio/proximity/mb1232.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/proximity/mb1232.c b/drivers/iio/proximity/mb1232.c
index fb1073c8d9f7..614e65cb9d42 100644
--- a/drivers/iio/proximity/mb1232.c
+++ b/drivers/iio/proximity/mb1232.c
@@ -76,7 +76,7 @@ static s16 mb1232_read_distance(struct mb1232_data *data)
 		goto error_unlock;
 	}
 
-	if (data->irqnr >= 0) {
+	if (data->irqnr > 0) {
 		/* it cannot take more than 100 ms */
 		ret = wait_for_completion_killable_timeout(&data->ranging,
 									HZ/10);
@@ -212,10 +212,7 @@ static int mb1232_probe(struct i2c_client *client)
 	init_completion(&data->ranging);
 
 	data->irqnr = fwnode_irq_get(dev_fwnode(&client->dev), 0);
-	if (data->irqnr <= 0) {
-		/* usage of interrupt is optional */
-		data->irqnr = -1;
-	} else {
+	if (data->irqnr > 0) {
 		ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq,
 				IRQF_TRIGGER_FALLING, id->name, indio_dev);
 		if (ret < 0) {
-- 
2.40.1


-- 
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 =] 

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[PATCH v8 2/8] iio: cdc: ad7150: relax return value check for IRQ get

[Matti Vaittinen]

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fwnode_irq_get[_byname]() were changed to not return 0 anymore. The
special error case where device-tree based IRQ mapping fails can't no
longer be reliably detected from this return value. This yields a
functional change in the driver where the mapping failure is treated as
an error.

The mapping failure can occur for example when the device-tree IRQ
information translation call-back(s) (xlate) fail, IRQ domain is not
found, IRQ type conflicts, etc. In most cases this indicates an error in
the device-tree and special handling is not really required.

One more thing to note is that ACPI APIs do not return zero for any
failures so this special handling did only apply on device-tree based
systems.

Drop the special handling for DT mapping failures as these can no longer
be separated from other errors at driver side. Change all failures in
IRQ getting to be handled by continuing without the events instead of
aborting the probe upon certain errors.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

---
Revision history:
v5 => v6:
 - Never abort the probe when IRQ getting fails but continue without
   events.

Please note that I don't have the hardware to test this change.
Furthermore, testing this type of device-tree error cases is not
trivial, as the question we probably dive in is "what happens with the
existing users who have errors in the device-tree". Answering to this
question is not simple.

The patch changing the fwnode_irq_get() got merged during 5.4:
https://lore.kernel.org/all/fb7241d3-d1d1-1c37-919b-488d6d007484@gmail.com/
This is a clean-up as agreed.
---
 drivers/iio/cdc/ad7150.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/cdc/ad7150.c b/drivers/iio/cdc/ad7150.c
index d656d2f12755..4c03b9e834b8 100644
--- a/drivers/iio/cdc/ad7150.c
+++ b/drivers/iio/cdc/ad7150.c
@@ -541,6 +541,7 @@ static int ad7150_probe(struct i2c_client *client)
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
 	struct ad7150_chip_info *chip;
 	struct iio_dev *indio_dev;
+	bool use_irq = true;
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
@@ -561,14 +562,13 @@ static int ad7150_probe(struct i2c_client *client)
 
 	chip->interrupts[0] = fwnode_irq_get(dev_fwnode(&client->dev), 0);
 	if (chip->interrupts[0] < 0)
-		return chip->interrupts[0];
-	if (id->driver_data == AD7150) {
+		use_irq = false;
+	else if (id->driver_data == AD7150) {
 		chip->interrupts[1] = fwnode_irq_get(dev_fwnode(&client->dev), 1);
 		if (chip->interrupts[1] < 0)
-			return chip->interrupts[1];
+			use_irq = false;
 	}
-	if (chip->interrupts[0] &&
-	    (id->driver_data == AD7151 || chip->interrupts[1])) {
+	if (use_irq) {
 		irq_set_status_flags(chip->interrupts[0], IRQ_NOAUTOEN);
 		ret = devm_request_threaded_irq(&client->dev,
 						chip->interrupts[0],
-- 
2.40.1


-- 
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 =] 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v8 1/8] iio: mb1232: relax return value check for IRQ get

[Jonathan Cameron]

On Tue, 1 Aug 2023 15:02:10 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> fwnode_irq_get() was changed to not return 0 anymore.
> 
> Drop check for return value 0.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> 
Applied fiddling above so I don't ack and sign off on it because
that confuses me :)

Applied to the togreg branch and pushed out as testing for all the
normal reasons.

Thanks,

Jonathan



> ---
> Revsion history:
> v5 =>:
> - No changes
> v4 => v5:
>  - drop unnecessary data->irqnr = -1 assignment
> 
> The patch changing the fwnode_irq_get() got merged during 5.4:
> https://lore.kernel.org/all/fb7241d3-d1d1-1c37-919b-488d6d007484@gmail.com/
> This is a clean-up as agreed.
> ---
>  drivers/iio/proximity/mb1232.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/proximity/mb1232.c b/drivers/iio/proximity/mb1232.c
> index fb1073c8d9f7..614e65cb9d42 100644
> --- a/drivers/iio/proximity/mb1232.c
> +++ b/drivers/iio/proximity/mb1232.c
> @@ -76,7 +76,7 @@ static s16 mb1232_read_distance(struct mb1232_data *data)
>  		goto error_unlock;
>  	}
>  
> -	if (data->irqnr >= 0) {
> +	if (data->irqnr > 0) {
>  		/* it cannot take more than 100 ms */
>  		ret = wait_for_completion_killable_timeout(&data->ranging,
>  									HZ/10);
> @@ -212,10 +212,7 @@ static int mb1232_probe(struct i2c_client *client)
>  	init_completion(&data->ranging);
>  
>  	data->irqnr = fwnode_irq_get(dev_fwnode(&client->dev), 0);
> -	if (data->irqnr <= 0) {
> -		/* usage of interrupt is optional */
> -		data->irqnr = -1;
> -	} else {
> +	if (data->irqnr > 0) {
>  		ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq,
>  				IRQF_TRIGGER_FALLING, id->name, indio_dev);
>  		if (ret < 0) {

Re: [PATCH v8 2/8] iio: cdc: ad7150: relax return value check for IRQ get

[Jonathan Cameron]

On Tue, 1 Aug 2023 15:02:47 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> fwnode_irq_get[_byname]() were changed to not return 0 anymore. The
> special error case where device-tree based IRQ mapping fails can't no
> longer be reliably detected from this return value. This yields a
> functional change in the driver where the mapping failure is treated as
> an error.
> 
> The mapping failure can occur for example when the device-tree IRQ
> information translation call-back(s) (xlate) fail, IRQ domain is not
> found, IRQ type conflicts, etc. In most cases this indicates an error in
> the device-tree and special handling is not really required.
> 
> One more thing to note is that ACPI APIs do not return zero for any
> failures so this special handling did only apply on device-tree based
> systems.
> 
> Drop the special handling for DT mapping failures as these can no longer
> be separated from other errors at driver side. Change all failures in
> IRQ getting to be handled by continuing without the events instead of
> aborting the probe upon certain errors.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Again, fiddled tags so I don't have RB and SoB

Applied to the togreg branch of iio.git and pushed out as testing for
all the normal reasons.

Thanks,

Jonathan

> 
> ---
> Revision history:
> v5 => v6:
>  - Never abort the probe when IRQ getting fails but continue without
>    events.
> 
> Please note that I don't have the hardware to test this change.
> Furthermore, testing this type of device-tree error cases is not
> trivial, as the question we probably dive in is "what happens with the
> existing users who have errors in the device-tree". Answering to this
> question is not simple.
> 
> The patch changing the fwnode_irq_get() got merged during 5.4:
> https://lore.kernel.org/all/fb7241d3-d1d1-1c37-919b-488d6d007484@gmail.com/
> This is a clean-up as agreed.
> ---
>  drivers/iio/cdc/ad7150.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/cdc/ad7150.c b/drivers/iio/cdc/ad7150.c
> index d656d2f12755..4c03b9e834b8 100644
> --- a/drivers/iio/cdc/ad7150.c
> +++ b/drivers/iio/cdc/ad7150.c
> @@ -541,6 +541,7 @@ static int ad7150_probe(struct i2c_client *client)
>  	const struct i2c_device_id *id = i2c_client_get_device_id(client);
>  	struct ad7150_chip_info *chip;
>  	struct iio_dev *indio_dev;
> +	bool use_irq = true;
>  	int ret;
>  
>  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
> @@ -561,14 +562,13 @@ static int ad7150_probe(struct i2c_client *client)
>  
>  	chip->interrupts[0] = fwnode_irq_get(dev_fwnode(&client->dev), 0);
>  	if (chip->interrupts[0] < 0)
> -		return chip->interrupts[0];
> -	if (id->driver_data == AD7150) {
> +		use_irq = false;
> +	else if (id->driver_data == AD7150) {
>  		chip->interrupts[1] = fwnode_irq_get(dev_fwnode(&client->dev), 1);
>  		if (chip->interrupts[1] < 0)
> -			return chip->interrupts[1];
> +			use_irq = false;
>  	}
> -	if (chip->interrupts[0] &&
> -	    (id->driver_data == AD7151 || chip->interrupts[1])) {
> +	if (use_irq) {
>  		irq_set_status_flags(chip->interrupts[0], IRQ_NOAUTOEN);
>  		ret = devm_request_threaded_irq(&client->dev,
>  						chip->interrupts[0],