From: Ramona Bolboaca ramona.bolboaca@analog.com
[ Upstream commit 99c05e4283a19a02a256f14100ca4ec3b2da3f62 ]
Add '__adis_enable_irq()' implementation which is the unlocked version of 'adis_enable_irq()'. Call '__adis_enable_irq()' instead of 'adis_enable_irq()' from '__adis_intial_startup()' to keep the expected unlocked functionality.
This fix is needed to remove a deadlock for all devices which are using 'adis_initial_startup()'. The deadlock occurs because the same mutex is acquired twice, without releasing it. The mutex is acquired once inside 'adis_initial_startup()', before calling '__adis_initial_startup()', and once inside 'adis_enable_irq()', which is called by '__adis_initial_startup()'. The deadlock is removed by calling '__adis_enable_irq()', instead of 'adis_enable_irq()' from within '__adis_initial_startup()'.
Fixes: b600bd7eb3335 ("iio: adis: do not disabe IRQs in 'adis_init()'") Signed-off-by: Ramona Bolboaca ramona.bolboaca@analog.com Reviewed-by: Nuno Sá nuno.sa@analog.com Link: https://lore.kernel.org/r/20221122082757.449452-2-ramona.bolboaca@analog.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/imu/adis.c | 28 ++++++++++------------------ include/linux/iio/imu/adis.h | 13 ++++++++++++- 2 files changed, 22 insertions(+), 19 deletions(-)
diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c index f7fcfd04f659..bc40240b29e2 100644 --- a/drivers/iio/imu/adis.c +++ b/drivers/iio/imu/adis.c @@ -270,23 +270,19 @@ EXPORT_SYMBOL_NS(adis_debugfs_reg_access, IIO_ADISLIB); #endif
/** - * adis_enable_irq() - Enable or disable data ready IRQ + * __adis_enable_irq() - Enable or disable data ready IRQ (unlocked) * @adis: The adis device * @enable: Whether to enable the IRQ * * Returns 0 on success, negative error code otherwise */ -int adis_enable_irq(struct adis *adis, bool enable) +int __adis_enable_irq(struct adis *adis, bool enable) { - int ret = 0; + int ret; u16 msc;
- mutex_lock(&adis->state_lock); - - if (adis->data->enable_irq) { - ret = adis->data->enable_irq(adis, enable); - goto out_unlock; - } + if (adis->data->enable_irq) + return adis->data->enable_irq(adis, enable);
if (adis->data->unmasked_drdy) { if (enable) @@ -294,12 +290,12 @@ int adis_enable_irq(struct adis *adis, bool enable) else disable_irq(adis->spi->irq);
- goto out_unlock; + return 0; }
ret = __adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc); if (ret) - goto out_unlock; + return ret;
msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH; msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2; @@ -308,13 +304,9 @@ int adis_enable_irq(struct adis *adis, bool enable) else msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;
- ret = __adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc); - -out_unlock: - mutex_unlock(&adis->state_lock); - return ret; + return __adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc); } -EXPORT_SYMBOL_NS(adis_enable_irq, IIO_ADISLIB); +EXPORT_SYMBOL_NS(__adis_enable_irq, IIO_ADISLIB);
/** * __adis_check_status() - Check the device for error conditions (unlocked) @@ -445,7 +437,7 @@ int __adis_initial_startup(struct adis *adis) * with 'IRQF_NO_AUTOEN' anyways. */ if (!adis->data->unmasked_drdy) - adis_enable_irq(adis, false); + __adis_enable_irq(adis, false);
if (!adis->data->prod_id_reg) return 0; diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h index 6193f9a6fbc2..8210a9e68215 100644 --- a/include/linux/iio/imu/adis.h +++ b/include/linux/iio/imu/adis.h @@ -406,9 +406,20 @@ static inline int adis_update_bits_base(struct adis *adis, unsigned int reg, __adis_update_bits_base(adis, reg, mask, val, 2)); \ })
-int adis_enable_irq(struct adis *adis, bool enable); int __adis_check_status(struct adis *adis); int __adis_initial_startup(struct adis *adis); +int __adis_enable_irq(struct adis *adis, bool enable); + +static inline int adis_enable_irq(struct adis *adis, bool enable) +{ + int ret; + + mutex_lock(&adis->state_lock); + ret = __adis_enable_irq(adis, enable); + mutex_unlock(&adis->state_lock); + + return ret; +}
static inline int adis_check_status(struct adis *adis) {