[PATCH v6 0/8] fix fwnode_irq_get[_byname()] returnvalue

[PATCH v6 0/8] fix fwnode_irq_get[_byname()] returnvalue

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 4341 bytes --]

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.

Here we change the fwnode_irq_get() and the fwnode_irq_get_byname() to
always return a negative errno upon failure.

I have audited following callers (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 the change. 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:
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):
  drivers: fwnode: fix fwnode_irq_get[_byname]()
  iio: mb1232: relax return value check for IRQ get
  net-next: mvpp2: 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
  iio: cdc: ad7150: relax return value check for IRQ get
  i2c: i2c-smbus: fwnode_irq_get_byname() return value fix

 drivers/base/property.c                         | 12 +++++++++---
 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 |  4 ++--
 drivers/pinctrl/nuvoton/pinctrl-wpcm450.c       |  2 --
 drivers/pinctrl/pinctrl-ingenic.c               |  2 --
 drivers/pinctrl/pinctrl-pistachio.c             |  6 ------
 8 files changed, 19 insertions(+), 26 deletions(-)


base-commit: f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6
-- 
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 --]
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[PATCH v6 1/8] drivers: fwnode: fix fwnode_irq_get[_byname]()

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 2463 bytes --]

The fwnode_irq_get() and the fwnode_irq_get_byname() return 0 upon
device-tree IRQ mapping failure. This is contradicting the
fwnode_irq_get_byname() function documentation and can potentially be a
source of errors like:

int probe(...) {
	...

	irq = fwnode_irq_get_byname();
	if (irq <= 0)
		return irq;

	...
}

Here we do correctly check the return value from fwnode_irq_get_byname()
but the driver probe will now return success. (There was already one
such user in-tree).

Change the fwnode_irq_get_byname() to work as documented and make also the
fwnode_irq_get() follow same common convention returning a negative errno
upon failure.

Fixes: ca0acb511c21 ("device property: Add fwnode_irq_get_byname")
Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

---
I dropped the existing reviewed-by tags because change to
fwnode_irq_get() was added.

Revision history:
v4 =>:
 - No Changes
v3 => v4:
 - Change also the fwnode_irq_get()
---
 drivers/base/property.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index f6117ec9805c..8c40abed7852 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -987,12 +987,18 @@ EXPORT_SYMBOL(fwnode_iomap);
  * @fwnode:	Pointer to the firmware node
  * @index:	Zero-based index of the IRQ
  *
- * Return: Linux IRQ number on success. Other values are determined
- * according to acpi_irq_get() or of_irq_get() operation.
+ * Return: Linux IRQ number on success. Negative errno on failure.
  */
 int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
 {
-	return fwnode_call_int_op(fwnode, irq_get, index);
+	int ret;
+
+	ret = fwnode_call_int_op(fwnode, irq_get, index);
+	/* We treat mapping errors as invalid case */
+	if (ret == 0)
+		return -EINVAL;
+
+	return ret;
 }
 EXPORT_SYMBOL(fwnode_irq_get);
 
-- 
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 --]
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[PATCH v6 2/8] iio: mb1232: relax return value check for IRQ get

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 1890 bytes --]

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 first patch of the series changes the fwnode_irq_get() so this depends
on the first patch of the series and should not be applied alone.
---
 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 e70cac8240af..3ae226297a00 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 =] 

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

[PATCH v6 3/8] net-next: mvpp2: relax return value check for IRQ get

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 1672 bytes --]

fwnode_irq_get[_byname]() were changed to not return 0 anymore.

Drop check for return value 0.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>

---
Revision history:
v5 =>:
 - No changes
v4 = v5:
Fix the subject, mb1232 => mvpp2

The first patch of the series changes the fwnode_irq_get() so this depends
on the first patch of the series and should not be applied alone.
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index adc953611913..5b987af306a5 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -5833,7 +5833,7 @@ static int mvpp2_multi_queue_vectors_init(struct mvpp2_port *port,
 			v->irq = of_irq_get_byname(port_node, irqname);
 		else
 			v->irq = fwnode_irq_get(port->fwnode, i);
-		if (v->irq <= 0) {
+		if (v->irq < 0) {
 			ret = -EINVAL;
 			goto err;
 		}
@@ -6764,7 +6764,7 @@ static int mvpp2_port_probe(struct platform_device *pdev,
 		err = -EPROBE_DEFER;
 		goto err_deinit_qvecs;
 	}
-	if (port->port_irq <= 0)
+	if (port->port_irq < 0)
 		/* the link irq is optional */
 		port->port_irq = 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 --]

[PATCH v6 4/8] pinctrl: wpcm450: relax return value check for IRQ get

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 2338 bytes --]

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 (no error, just skip the IRQ) handling for DT mapping
failures as these can no longer be separated from other errors at driver
side.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

---
Revision history:
v5 => :
 - No changes
v4 => v5:
Fix typo in subject "elax" => "relax"

Please note, I took Linus' reply to v4 cover-letter as ack && added the
tag. Please let me know if this was not Ok.

The first patch of the series changes the fwnode_irq_get() so this depends
on the first patch of the series and should not be applied alone.
---
 drivers/pinctrl/nuvoton/pinctrl-wpcm450.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c b/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c
index 2d1c1652cfd9..f9326210b5eb 100644
--- a/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c
+++ b/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c
@@ -1106,8 +1106,6 @@ static int wpcm450_gpio_register(struct platform_device *pdev,
 			irq = fwnode_irq_get(child, i);
 			if (irq < 0)
 				break;
-			if (!irq)
-				continue;
 
 			girq->parents[i] = irq;
 			girq->num_parents++;
-- 
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 --]

[PATCH v6 5/8] pinctrl: ingenic: relax return value check for IRQ get

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 1453 bytes --]

fwnode_irq_get[_byname]() were changed to not return 0 anymore.

Drop check for return value 0.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

---
Revision history:
 - No changes

Please note, I took Linus' reply to v4 cover-letter as ack && added the
tag. Please let me know if this was not Ok.

The first patch of the series changes the fwnode_irq_get() so this depends
on the first patch of the series and should not be applied alone.
---
 drivers/pinctrl/pinctrl-ingenic.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-ingenic.c b/drivers/pinctrl/pinctrl-ingenic.c
index 2f220a47b749..86e71ad703a5 100644
--- a/drivers/pinctrl/pinctrl-ingenic.c
+++ b/drivers/pinctrl/pinctrl-ingenic.c
@@ -4201,8 +4201,6 @@ static int __init ingenic_gpio_probe(struct ingenic_pinctrl *jzpc,
 	err = fwnode_irq_get(fwnode, 0);
 	if (err < 0)
 		return err;
-	if (!err)
-		return -EINVAL;
 	jzgc->irq = err;
 
 	girq = &jzgc->gc.irq;
-- 
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 --]

[PATCH v6 6/8] pinctrl: pistachio: relax return value check for IRQ get

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 1548 bytes --]

fwnode_irq_get[_byname]() were changed to not return 0 anymore.

Drop check for return value 0.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

---
Revision history:
 - No changes

Please note, I took Linus' reply to v4 cover-letter as ack && added the
tag. Please let me know if this was not Ok.

The first patch of the series changes the fwnode_irq_get() so this depends
on the first patch of the series and should not be applied alone.
---
 drivers/pinctrl/pinctrl-pistachio.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-pistachio.c b/drivers/pinctrl/pinctrl-pistachio.c
index 53408344927a..8c50e0091b32 100644
--- a/drivers/pinctrl/pinctrl-pistachio.c
+++ b/drivers/pinctrl/pinctrl-pistachio.c
@@ -1393,12 +1393,6 @@ static int pistachio_gpio_register(struct pistachio_pinctrl *pctl)
 			dev_err(pctl->dev, "Failed to retrieve IRQ for bank %u\n", i);
 			goto err;
 		}
-		if (!ret) {
-			fwnode_handle_put(child);
-			dev_err(pctl->dev, "No IRQ for bank %u\n", i);
-			ret = -EINVAL;
-			goto err;
-		}
 		irq = ret;
 
 		bank = &pctl->gpio_banks[i];
-- 
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 --]

[PATCH v6 7/8] iio: cdc: ad7150: relax return value check for IRQ get

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 3264 bytes --]

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>

---
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 first patch of the series changes the fwnode_irq_get() so this depends
on the first patch of the series and should not be applied alone.
---
 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 79aeb0aaea67..c05e078bba16 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 --]

[PATCH v6 8/8] i2c: i2c-smbus: fwnode_irq_get_byname() return value fix

[Matti Vaittinen]

[-- Attachment #1: Type: text/plain, Size: 1957 bytes --]

The fwnode_irq_get_byname() was changed to not return 0 upon failure so
return value check can be adjusted to reflect the change.

Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>

---
Revision history:
v5 =>:
 - No changes
v4 => v5:
 - Added back after this was accidentally dropped at v4.

Depends on the mentioned return value change which is in patch 1/2. The
return value change does also cause a functional change here. Eg. when
IRQ mapping fails, the fwnode_irq_get_byname() no longer returns zero.
This will cause also the probe here to return nonzero failure. I guess
this is desired behaviour - but I would appreciate any confirmation.

Please, see also previous discussion here:
https://lore.kernel.org/all/fbd52f5f5253b382b8d7b3e8046134de29f965b8.1666710197.git.mazziesaccount@gmail.com/

Another suggestion has been to drop the check altogether. I am slightly
reluctant on doing that unless it gets confirmed that is the "right
thing to do".
---
 drivers/i2c/i2c-smbus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index 138c3f5e0093..893fe7cd3e41 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -129,7 +129,7 @@ static int smbalert_probe(struct i2c_client *ara)
 	} else {
 		irq = fwnode_irq_get_byname(dev_fwnode(adapter->dev.parent),
 					    "smbus_alert");
-		if (irq <= 0)
+		if (irq < 0)
 			return irq;
 	}
 
-- 
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 v6 7/8] iio: cdc: ad7150: relax return value check for IRQ get

[Jonathan Cameron]

On Fri, 26 May 2023 09:39:14 +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>

I think this is the best we can do, though ideally I'd like to have
seen errors due to not being provided by firmware passed through and
firmware bug issues (where it provides an irq we can't get for some reason
shouted about - with the driver failing to probe.)

Still, it's an improvement and for some FW old code wouldn't have
done this either. Hence let's go with this approach.

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 first patch of the series changes the fwnode_irq_get() so this depends
> on the first patch of the series and should not be applied alone.
> ---
>  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 79aeb0aaea67..c05e078bba16 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],

Re: [PATCH v6 8/8] i2c: i2c-smbus: fwnode_irq_get_byname() return value fix

[Jonathan Cameron]

On Fri, 26 May 2023 09:39:37 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> The fwnode_irq_get_byname() was changed to not return 0 upon failure so
> return value check can be adjusted to reflect the change.
> 
> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> 

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Comments follow though...
> ---
> Revision history:
> v5 =>:
>  - No changes
> v4 => v5:
>  - Added back after this was accidentally dropped at v4.
> 
> Depends on the mentioned return value change which is in patch 1/2. The

1/8?  Or just use 1/N and you never have to update it.

> return value change does also cause a functional change here. Eg. when
> IRQ mapping fails, the fwnode_irq_get_byname() no longer returns zero.
> This will cause also the probe here to return nonzero failure. I guess
> this is desired behaviour - but I would appreciate any confirmation.
> 
> Please, see also previous discussion here:
> https://lore.kernel.org/all/fbd52f5f5253b382b8d7b3e8046134de29f965b8.1666710197.git.mazziesaccount@gmail.com/
> 
> Another suggestion has been to drop the check altogether. I am slightly
> reluctant on doing that unless it gets confirmed that is the "right
> thing to do".

I'd be more inclined to also fail in the setup->irq < 0 path and drop the later check
on basis I can't see the driver doing anything useful wtihout an interrupt.

> ---
>  drivers/i2c/i2c-smbus.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
> index 138c3f5e0093..893fe7cd3e41 100644
> --- a/drivers/i2c/i2c-smbus.c
> +++ b/drivers/i2c/i2c-smbus.c
> @@ -129,7 +129,7 @@ static int smbalert_probe(struct i2c_client *ara)
>  	} else {
>  		irq = fwnode_irq_get_byname(dev_fwnode(adapter->dev.parent),
>  					    "smbus_alert");
> -		if (irq <= 0)
> +		if (irq < 0)
>  			return irq;
>  	}
>  

Re: [PATCH v6 6/8] pinctrl: pistachio: relax return value check for IRQ get

[Jonathan Cameron]

On Fri, 26 May 2023 09:38:58 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> fwnode_irq_get[_byname]() were changed to not return 0 anymore.
> 
> Drop check for return value 0.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
> 
> ---
> Revision history:
>  - No changes
> 
> Please note, I took Linus' reply to v4 cover-letter as ack && added the
> tag. Please let me know if this was not Ok.

Whilst I understand your point as Linus said he'd pick the patches up,
I would have left it to Linus to Ack explicitly but added a note here
to say he basically already did.

LGTM
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> The first patch of the series changes the fwnode_irq_get() so this depends
> on the first patch of the series and should not be applied alone.
> ---
>  drivers/pinctrl/pinctrl-pistachio.c | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-pistachio.c b/drivers/pinctrl/pinctrl-pistachio.c
> index 53408344927a..8c50e0091b32 100644
> --- a/drivers/pinctrl/pinctrl-pistachio.c
> +++ b/drivers/pinctrl/pinctrl-pistachio.c
> @@ -1393,12 +1393,6 @@ static int pistachio_gpio_register(struct pistachio_pinctrl *pctl)
>  			dev_err(pctl->dev, "Failed to retrieve IRQ for bank %u\n", i);
>  			goto err;
>  		}
> -		if (!ret) {
> -			fwnode_handle_put(child);
> -			dev_err(pctl->dev, "No IRQ for bank %u\n", i);
> -			ret = -EINVAL;
> -			goto err;
> -		}
>  		irq = ret;
>  
>  		bank = &pctl->gpio_banks[i];

Re: [PATCH v6 5/8] pinctrl: ingenic: relax return value check for IRQ get

[Jonathan Cameron]

On Fri, 26 May 2023 09:38:39 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> fwnode_irq_get[_byname]() were changed to not return 0 anymore.
> 
> Drop check for return value 0.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Reviewed-by: Paul Cercueil <paul@crapouillou.net>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
> 
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> Revision history:
>  - No changes
> 
> Please note, I took Linus' reply to v4 cover-letter as ack && added the
> tag. Please let me know if this was not Ok.
> 
> The first patch of the series changes the fwnode_irq_get() so this depends
> on the first patch of the series and should not be applied alone.
> ---
>  drivers/pinctrl/pinctrl-ingenic.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-ingenic.c b/drivers/pinctrl/pinctrl-ingenic.c
> index 2f220a47b749..86e71ad703a5 100644
> --- a/drivers/pinctrl/pinctrl-ingenic.c
> +++ b/drivers/pinctrl/pinctrl-ingenic.c
> @@ -4201,8 +4201,6 @@ static int __init ingenic_gpio_probe(struct ingenic_pinctrl *jzpc,
>  	err = fwnode_irq_get(fwnode, 0);
>  	if (err < 0)
>  		return err;
> -	if (!err)
> -		return -EINVAL;
>  	jzgc->irq = err;
>  
>  	girq = &jzgc->gc.irq;

Re: [PATCH v6 4/8] pinctrl: wpcm450: relax return value check for IRQ get

[Jonathan Cameron]

On Fri, 26 May 2023 09:38:05 +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 (no error, just skip the IRQ) handling for DT mapping
> failures as these can no longer be separated from other errors at driver
> side.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
> 
Seems fine

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> Revision history:
> v5 => :
>  - No changes
> v4 => v5:
> Fix typo in subject "elax" => "relax"
> 
> Please note, I took Linus' reply to v4 cover-letter as ack && added the
> tag. Please let me know if this was not Ok.
> 
> The first patch of the series changes the fwnode_irq_get() so this depends
> on the first patch of the series and should not be applied alone.
> ---
>  drivers/pinctrl/nuvoton/pinctrl-wpcm450.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c b/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c
> index 2d1c1652cfd9..f9326210b5eb 100644
> --- a/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c
> +++ b/drivers/pinctrl/nuvoton/pinctrl-wpcm450.c
> @@ -1106,8 +1106,6 @@ static int wpcm450_gpio_register(struct platform_device *pdev,
>  			irq = fwnode_irq_get(child, i);
>  			if (irq < 0)
>  				break;
> -			if (!irq)
> -				continue;
>  
>  			girq->parents[i] = irq;
>  			girq->num_parents++;

Re: [PATCH v6 3/8] net-next: mvpp2: relax return value check for IRQ get

[Jonathan Cameron]

On Fri, 26 May 2023 09:36:57 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> fwnode_irq_get[_byname]() were changed to not return 0 anymore.
> 
> Drop check for return value 0.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> 
Seems straight forward though 'maybe' nice to return the actual
error rather than eating it.  That relies on nothing up the stack
handling resulting error codes different though.


> ---
> Revision history:
> v5 =>:
>  - No changes
> v4 = v5:
> Fix the subject, mb1232 => mvpp2
> 
> The first patch of the series changes the fwnode_irq_get() so this depends
> on the first patch of the series and should not be applied alone.
> ---
>  drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index adc953611913..5b987af306a5 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -5833,7 +5833,7 @@ static int mvpp2_multi_queue_vectors_init(struct mvpp2_port *port,
>  			v->irq = of_irq_get_byname(port_node, irqname);
>  		else
>  			v->irq = fwnode_irq_get(port->fwnode, i);
> -		if (v->irq <= 0) {
> +		if (v->irq < 0) {
>  			ret = -EINVAL;

			ret = v->irq; seems nicer.

>  			goto err;
>  		}
> @@ -6764,7 +6764,7 @@ static int mvpp2_port_probe(struct platform_device *pdev,
>  		err = -EPROBE_DEFER;
>  		goto err_deinit_qvecs;
>  	}
> -	if (port->port_irq <= 0)
> +	if (port->port_irq < 0)
>  		/* the link irq is optional */
>  		port->port_irq = 0;
>  

Re: [PATCH v6 1/8] drivers: fwnode: fix fwnode_irq_get[_byname]()

[Jonathan Cameron]

On Fri, 26 May 2023 09:35:30 +0300
Matti Vaittinen <mazziesaccount@gmail.com> wrote:

> The fwnode_irq_get() and the fwnode_irq_get_byname() return 0 upon
> device-tree IRQ mapping failure. This is contradicting the
> fwnode_irq_get_byname() function documentation and can potentially be a
> source of errors like:
> 
> int probe(...) {
> 	...
> 
> 	irq = fwnode_irq_get_byname();
> 	if (irq <= 0)
> 		return irq;
> 
> 	...
> }
> 
> Here we do correctly check the return value from fwnode_irq_get_byname()
> but the driver probe will now return success. (There was already one
> such user in-tree).
> 
> Change the fwnode_irq_get_byname() to work as documented and make also the
> fwnode_irq_get() follow same common convention returning a negative errno
> upon failure.
> 
> Fixes: ca0acb511c21 ("device property: Add fwnode_irq_get_byname")
> Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Suggested-by: Jonathan Cameron <jic23@kernel.org>
> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> 
This bothers me a little because there may be drivers that haven't been
caught yet that assume the zero value.   Still this is more consistent
with what I'd expect to happen, so fair enough

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>


> ---
> I dropped the existing reviewed-by tags because change to
> fwnode_irq_get() was added.
> 
> Revision history:
> v4 =>:
>  - No Changes
> v3 => v4:
>  - Change also the fwnode_irq_get()
> ---
>  drivers/base/property.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index f6117ec9805c..8c40abed7852 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -987,12 +987,18 @@ EXPORT_SYMBOL(fwnode_iomap);
>   * @fwnode:	Pointer to the firmware node
>   * @index:	Zero-based index of the IRQ
>   *
> - * Return: Linux IRQ number on success. Other values are determined
> - * according to acpi_irq_get() or of_irq_get() operation.
> + * Return: Linux IRQ number on success. Negative errno on failure.
>   */
>  int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
>  {
> -	return fwnode_call_int_op(fwnode, irq_get, index);
> +	int ret;
> +
> +	ret = fwnode_call_int_op(fwnode, irq_get, index);
> +	/* We treat mapping errors as invalid case */
> +	if (ret == 0)
> +		return -EINVAL;
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL(fwnode_irq_get);
>