From 743cc37561188e222eff5200d4507eabcccf9d41 Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Thu, 9 Mar 2017 10:21:59 -0600 Subject: [PATCH] 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 Signed-off-by: Peter Rosin --- drivers/i2c/muxes/i2c-mux-pca954x.c | 12 ++++++------ 1 file 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, -- 2.20.1