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authorJulia Cartwright <julia@ni.com>2017-03-09 10:21:59 -0600
committerPeter Rosin <peda@axentia.se>2017-03-15 23:22:43 +0100
commit743cc37561188e222eff5200d4507eabcccf9d41 (patch)
treed4beb7c8e16a88ba2ff11e5bdb0bd2979add5af3 /drivers/i2c
parent4495c08e84729385774601b5146d51d9e5849f81 (diff)
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: Julia Cartwright <julia@ni.com> Signed-off-by: Peter Rosin <peda@axentia.se>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index dfc1c0e37c40..15dfc1648716 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -85,7 +85,7 @@ struct pca954x {
struct irq_domain *irq;
unsigned int irq_mask;
- spinlock_t lock;
+ raw_spinlock_t lock;
};
/* Provide specs for the PCA954x types we know about */
@@ -264,13 +264,13 @@ static void pca954x_irq_mask(struct irq_data *idata)
unsigned int pos = idata->hwirq;
unsigned long flags;
- spin_lock_irqsave(&data->lock, flags);
+ raw_spin_lock_irqsave(&data->lock, flags);
data->irq_mask &= ~BIT(pos);
if (!data->irq_mask)
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)
@@ -279,13 +279,13 @@ static void pca954x_irq_unmask(struct irq_data *idata)
unsigned int pos = idata->hwirq;
unsigned long flags;
- spin_lock_irqsave(&data->lock, flags);
+ raw_spin_lock_irqsave(&data->lock, flags);
if (!data->irq_mask)
enable_irq(data->client->irq);
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)
@@ -311,7 +311,7 @@ static int pca954x_irq_setup(struct i2c_mux_core *muxc)
if (!data->chip->has_irq || client->irq <= 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->chip->nchans,