Commit 743cc375 authored by Julia Cartwright's avatar Julia Cartwright Committed by Peter Rosin

i2c: mux: pca954x: make use of raw_spinlock variants

The pca954x i2c mux driver currently implements an irq_chip for handling
interrupts; due to how irq_chip handling is done, it's necessary for the
irq_chip methods to be invoked from hardirq context, even on a a
real-time kernel.  Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.

A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw spinlock.
Signed-off-by: default avatarJulia Cartwright <julia@ni.com>
Signed-off-by: default avatarPeter Rosin <peda@axentia.se>
parent 4495c08e
...@@ -85,7 +85,7 @@ struct pca954x { ...@@ -85,7 +85,7 @@ struct pca954x {
struct irq_domain *irq; struct irq_domain *irq;
unsigned int irq_mask; unsigned int irq_mask;
spinlock_t lock; raw_spinlock_t lock;
}; };
/* Provide specs for the PCA954x types we know about */ /* Provide specs for the PCA954x types we know about */
...@@ -264,13 +264,13 @@ static void pca954x_irq_mask(struct irq_data *idata) ...@@ -264,13 +264,13 @@ static void pca954x_irq_mask(struct irq_data *idata)
unsigned int pos = idata->hwirq; unsigned int pos = idata->hwirq;
unsigned long flags; unsigned long flags;
spin_lock_irqsave(&data->lock, flags); raw_spin_lock_irqsave(&data->lock, flags);
data->irq_mask &= ~BIT(pos); data->irq_mask &= ~BIT(pos);
if (!data->irq_mask) if (!data->irq_mask)
disable_irq(data->client->irq); disable_irq(data->client->irq);
spin_unlock_irqrestore(&data->lock, flags); raw_spin_unlock_irqrestore(&data->lock, flags);
} }
static void pca954x_irq_unmask(struct irq_data *idata) static void pca954x_irq_unmask(struct irq_data *idata)
...@@ -279,13 +279,13 @@ static void pca954x_irq_unmask(struct irq_data *idata) ...@@ -279,13 +279,13 @@ static void pca954x_irq_unmask(struct irq_data *idata)
unsigned int pos = idata->hwirq; unsigned int pos = idata->hwirq;
unsigned long flags; unsigned long flags;
spin_lock_irqsave(&data->lock, flags); raw_spin_lock_irqsave(&data->lock, flags);
if (!data->irq_mask) if (!data->irq_mask)
enable_irq(data->client->irq); enable_irq(data->client->irq);
data->irq_mask |= BIT(pos); data->irq_mask |= BIT(pos);
spin_unlock_irqrestore(&data->lock, flags); raw_spin_unlock_irqrestore(&data->lock, flags);
} }
static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type) static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
...@@ -311,7 +311,7 @@ static int pca954x_irq_setup(struct i2c_mux_core *muxc) ...@@ -311,7 +311,7 @@ static int pca954x_irq_setup(struct i2c_mux_core *muxc)
if (!data->chip->has_irq || client->irq <= 0) if (!data->chip->has_irq || client->irq <= 0)
return 0; return 0;
spin_lock_init(&data->lock); raw_spin_lock_init(&data->lock);
data->irq = irq_domain_add_linear(client->dev.of_node, data->irq = irq_domain_add_linear(client->dev.of_node,
data->chip->nchans, data->chip->nchans,
......
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