| Message ID | cover.1684220962.git.mazziesaccount@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | fix fwnode_irq_get[_byname()] returnvalue | expand |
On Tue, May 16, 2023 at 9:12 AM Matti Vaittinen <mazziesaccount@gmail.com> wrote: > 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: Also, zero is not really a valid IRQ, it means NO_IRQ: https://lwn.net/Articles/470820/ I'll apply the pinctrl patches. Yours, Linus Walleij
On 5/17/23 15:43, Linus Walleij wrote: > On Tue, May 16, 2023 at 9:12 AM Matti Vaittinen > <mazziesaccount@gmail.com> wrote: > >> 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: > > Also, zero is not really a valid IRQ, it means NO_IRQ: > https://lwn.net/Articles/470820/ > > I'll apply the pinctrl patches. Thanks Linus. I guess you noticed but please wait until the patch 1/7 gets in as the pinctrl patches won't do "the right thing" without it. (Just ensuring we are on a same page ;) ) Yours, -- Matti
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 will gain functional change as well. Here the logic is less straightforward but boils down to the same question as with the pinctrl-wpcm450.c. Should all the IRQ getting errors jump to same 'no-IRQ' branch as the DT mapping error, or should the DT mapping error abort the probe with error same way as other IRQ getting failures do? Revision history: 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 (7): drivers: fwnode: fix fwnode_irq_get[_byname]() iio: mb1232: relax return value check for IRQ get net-next: mb1232: relax return value check for IRQ get pinctrl: wpcm450: elax 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: Functional change drivers/base/property.c | 12 +++++++++--- drivers/iio/cdc/ad7150.c | 3 +-- drivers/iio/proximity/mb1232.c | 4 ++-- 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 ------ 7 files changed, 14 insertions(+), 19 deletions(-) base-commit: f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6