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spi: Lock controller idling transition inside the io_mutex

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This way, the spi sync path does not need to deal with the idling
transition.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-4-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
David Jander 2022-06-21 08:12:26 +02:00 committed by Mark Brown
parent ae7d2346dc
commit c1038165fb
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GPG Key ID: 24D68B725D5487D0
1 changed files with 12 additions and 6 deletions
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18
drivers/spi/spi.c
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@ -1643,27 +1643,30 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
unsigned long flags;
int ret;
/* Take the IO mutex */
mutex_lock(&ctlr->io_mutex);
/* Lock queue */
spin_lock_irqsave(&ctlr->queue_lock, flags);
/* Make sure we are not already running a message */
if (ctlr->cur_msg) {
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
return;
goto out_unlock;
}
/* If another context is idling the device then defer */
if (ctlr->idling) {
kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
return;
goto out_unlock;
}
/* Check if the queue is idle */
if (list_empty(&ctlr->queue) || !ctlr->running) {
if (!ctlr->busy) {
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
return;
goto out_unlock;
}
/* Defer any non-atomic teardown to the thread */
@ -1679,7 +1682,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
&ctlr->pump_messages);
}
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
return;
goto out_unlock;
}
ctlr->busy = false;
@ -1701,7 +1704,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
ctlr->idling = false;
ctlr->queue_empty = true;
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
return;
goto out_unlock;
}
/* Extract head of queue */
@ -1715,13 +1718,16 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
ctlr->busy = true;
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
mutex_lock(&ctlr->io_mutex);
ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
mutex_unlock(&ctlr->io_mutex);
/* Prod the scheduler in case transfer_one() was busy waiting */
if (!ret)
cond_resched();
return;
out_unlock:
mutex_unlock(&ctlr->io_mutex);
}
/**