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mfd: t7l66xb: Make use of raw_spinlock variants 

The t7l66xb mfd 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: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Julia Cartwright 2017-03-21 17:43:05 -05:00 committed by Lee Jones
parent 93ad447191
commit 9fe8c2dfe1
1 changed files with 10 additions and 10 deletions
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20
drivers/mfd/t7l66xb.c
View File

@ -69,7 +69,7 @@ static const struct resource t7l66xb_mmc_resources[] = {
struct t7l66xb { struct t7l66xb {
void __iomem *scr; void __iomem *scr;
/* Lock to protect registers requiring read/modify/write ops. */ /* Lock to protect registers requiring read/modify/write ops. */
spinlock_t lock; raw_spinlock_t lock;
struct resource rscr; struct resource rscr;
struct clk *clk48m; struct clk *clk48m;
@ -89,13 +89,13 @@ static int t7l66xb_mmc_enable(struct platform_device *mmc)
clk_prepare_enable(t7l66xb->clk32k); clk_prepare_enable(t7l66xb->clk32k);
spin_lock_irqsave(&t7l66xb->lock, flags); raw_spin_lock_irqsave(&t7l66xb->lock, flags);
dev_ctl = tmio_ioread8(t7l66xb->scr + SCR_DEV_CTL); dev_ctl = tmio_ioread8(t7l66xb->scr + SCR_DEV_CTL);
dev_ctl |= SCR_DEV_CTL_MMC; dev_ctl |= SCR_DEV_CTL_MMC;
tmio_iowrite8(dev_ctl, t7l66xb->scr + SCR_DEV_CTL); tmio_iowrite8(dev_ctl, t7l66xb->scr + SCR_DEV_CTL);
spin_unlock_irqrestore(&t7l66xb->lock, flags); raw_spin_unlock_irqrestore(&t7l66xb->lock, flags);
tmio_core_mmc_enable(t7l66xb->scr + 0x200, 0, tmio_core_mmc_enable(t7l66xb->scr + 0x200, 0,
t7l66xb_mmc_resources[0].start & 0xfffe); t7l66xb_mmc_resources[0].start & 0xfffe);
@ -110,13 +110,13 @@ static int t7l66xb_mmc_disable(struct platform_device *mmc)
unsigned long flags; unsigned long flags;
u8 dev_ctl; u8 dev_ctl;
spin_lock_irqsave(&t7l66xb->lock, flags); raw_spin_lock_irqsave(&t7l66xb->lock, flags);
dev_ctl = tmio_ioread8(t7l66xb->scr + SCR_DEV_CTL); dev_ctl = tmio_ioread8(t7l66xb->scr + SCR_DEV_CTL);
dev_ctl &= ~SCR_DEV_CTL_MMC; dev_ctl &= ~SCR_DEV_CTL_MMC;
tmio_iowrite8(dev_ctl, t7l66xb->scr + SCR_DEV_CTL); tmio_iowrite8(dev_ctl, t7l66xb->scr + SCR_DEV_CTL);
spin_unlock_irqrestore(&t7l66xb->lock, flags); raw_spin_unlock_irqrestore(&t7l66xb->lock, flags);
clk_disable_unprepare(t7l66xb->clk32k); clk_disable_unprepare(t7l66xb->clk32k);
@ -206,11 +206,11 @@ static void t7l66xb_irq_mask(struct irq_data *data)
unsigned long flags; unsigned long flags;
u8 imr; u8 imr;
spin_lock_irqsave(&t7l66xb->lock, flags); raw_spin_lock_irqsave(&t7l66xb->lock, flags);
imr = tmio_ioread8(t7l66xb->scr + SCR_IMR); imr = tmio_ioread8(t7l66xb->scr + SCR_IMR);
imr |= 1 << (data->irq - t7l66xb->irq_base); imr |= 1 << (data->irq - t7l66xb->irq_base);
tmio_iowrite8(imr, t7l66xb->scr + SCR_IMR); tmio_iowrite8(imr, t7l66xb->scr + SCR_IMR);
spin_unlock_irqrestore(&t7l66xb->lock, flags); raw_spin_unlock_irqrestore(&t7l66xb->lock, flags);
} }
static void t7l66xb_irq_unmask(struct irq_data *data) static void t7l66xb_irq_unmask(struct irq_data *data)
@ -219,11 +219,11 @@ static void t7l66xb_irq_unmask(struct irq_data *data)
unsigned long flags; unsigned long flags;
u8 imr; u8 imr;
spin_lock_irqsave(&t7l66xb->lock, flags); raw_spin_lock_irqsave(&t7l66xb->lock, flags);
imr = tmio_ioread8(t7l66xb->scr + SCR_IMR); imr = tmio_ioread8(t7l66xb->scr + SCR_IMR);
imr &= ~(1 << (data->irq - t7l66xb->irq_base)); imr &= ~(1 << (data->irq - t7l66xb->irq_base));
tmio_iowrite8(imr, t7l66xb->scr + SCR_IMR); tmio_iowrite8(imr, t7l66xb->scr + SCR_IMR);
spin_unlock_irqrestore(&t7l66xb->lock, flags); raw_spin_unlock_irqrestore(&t7l66xb->lock, flags);
} }
static struct irq_chip t7l66xb_chip = { static struct irq_chip t7l66xb_chip = {
@ -321,7 +321,7 @@ static int t7l66xb_probe(struct platform_device *dev)
if (!t7l66xb) if (!t7l66xb)
return -ENOMEM; return -ENOMEM;
spin_lock_init(&t7l66xb->lock); raw_spin_lock_init(&t7l66xb->lock);
platform_set_drvdata(dev, t7l66xb); platform_set_drvdata(dev, t7l66xb);