From 1c297a66654a3295ae87e2b7f3724d214eb2b5ec Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Mon, 1 Jul 2013 15:20:00 +0100 Subject: iio: Fix iio_channel_has_info Since the info_mask split, iio_channel_has_info() is not working correctly. info_mask_separate and info_mask_shared_by_type, it is not possible to compare them directly with the iio_chan_info_enum enum. Correct that bit using the BIT() macro. Cc: # 3.10.x Signed-off-by: Alexandre Belloni Signed-off-by: Jonathan Cameron --- include/linux/iio/iio.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/iio') diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 8d171f427632..3d35b7023591 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -211,8 +211,8 @@ struct iio_chan_spec { static inline bool iio_channel_has_info(const struct iio_chan_spec *chan, enum iio_chan_info_enum type) { - return (chan->info_mask_separate & type) | - (chan->info_mask_shared_by_type & type); + return (chan->info_mask_separate & BIT(type)) | + (chan->info_mask_shared_by_type & BIT(type)); } #define IIO_ST(si, rb, sb, sh) \ -- cgit v1.2.3 From a1a8e1dc111d6f05e7164e851e58219d428359e1 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 16 Jul 2013 15:28:00 +0100 Subject: iio:trigger: Fix use_count race condition When using more than one trigger consumer it can happen that multiple threads perform a read-modify-update cycle on 'use_count' concurrently. This can cause updates to be lost and use_count can get stuck at non-zero value, in which case the IIO core assumes that at least one thread is still running and will wait for it to finish before running any trigger handlers again. This effectively renders the trigger disabled and a reboot is necessary before it can be used again. To fix this make use_count an atomic variable. Also set it to the number of consumers before starting the first consumer, otherwise it might happen that use_count drops to 0 even though not all consumers have been run yet. Signed-off-by: Lars-Peter Clausen Tested-by: Denis Ciocca Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-trigger.c | 34 ++++++++++++++++++++++------------ include/linux/iio/trigger.h | 3 ++- 2 files changed, 24 insertions(+), 13 deletions(-) (limited to 'include/linux/iio') diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c index ea8a4146620d..0dd9bb873130 100644 --- a/drivers/iio/industrialio-trigger.c +++ b/drivers/iio/industrialio-trigger.c @@ -127,12 +127,17 @@ static struct iio_trigger *iio_trigger_find_by_name(const char *name, void iio_trigger_poll(struct iio_trigger *trig, s64 time) { int i; - if (!trig->use_count) - for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) - if (trig->subirqs[i].enabled) { - trig->use_count++; + + if (!atomic_read(&trig->use_count)) { + atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER); + + for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { + if (trig->subirqs[i].enabled) generic_handle_irq(trig->subirq_base + i); - } + else + iio_trigger_notify_done(trig); + } + } } EXPORT_SYMBOL(iio_trigger_poll); @@ -146,19 +151,24 @@ EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll); void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time) { int i; - if (!trig->use_count) - for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) - if (trig->subirqs[i].enabled) { - trig->use_count++; + + if (!atomic_read(&trig->use_count)) { + atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER); + + for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { + if (trig->subirqs[i].enabled) handle_nested_irq(trig->subirq_base + i); - } + else + iio_trigger_notify_done(trig); + } + } } EXPORT_SYMBOL(iio_trigger_poll_chained); void iio_trigger_notify_done(struct iio_trigger *trig) { - trig->use_count--; - if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable) + if (atomic_dec_and_test(&trig->use_count) && trig->ops && + trig->ops->try_reenable) if (trig->ops->try_reenable(trig)) /* Missed an interrupt so launch new poll now */ iio_trigger_poll(trig, 0); diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h index 3869c525b052..369cf2cd5144 100644 --- a/include/linux/iio/trigger.h +++ b/include/linux/iio/trigger.h @@ -8,6 +8,7 @@ */ #include #include +#include #ifndef _IIO_TRIGGER_H_ #define _IIO_TRIGGER_H_ @@ -61,7 +62,7 @@ struct iio_trigger { struct list_head list; struct list_head alloc_list; - int use_count; + atomic_t use_count; struct irq_chip subirq_chip; int subirq_base; -- cgit v1.2.3