[PATCH] mfd: ti_am335x_tscadc: avoid possible deadlock of reg_lock

From: Sebastian Andrzej Siewior
Date: Tue Oct 22 2013 - 10:12:59 EST


Since the addition of continuous sampling mode and shared irq support,
the reg_lock lock can be taken with and without interrupts. This patch
uses the *_irq* variant which should be used in order to avaoid a deadlock.

Cc: Zubair Lutfullah <zubair.lutfullah@xxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
drivers/mfd/ti_am335x_tscadc.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index baaf5a8..912a41f 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -56,21 +56,25 @@ EXPORT_SYMBOL_GPL(am335x_tsc_se_update);

void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val)
{
- spin_lock(&tsadc->reg_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&tsadc->reg_lock, flags);
tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE);
tsadc->reg_se_cache |= val;
am335x_tsc_se_update(tsadc);
- spin_unlock(&tsadc->reg_lock);
+ spin_unlock_irqrestore(&tsadc->reg_lock, flags);
}
EXPORT_SYMBOL_GPL(am335x_tsc_se_set);

void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
{
- spin_lock(&tsadc->reg_lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&tsadc->reg_lock, flags);
tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE);
tsadc->reg_se_cache &= ~val;
am335x_tsc_se_update(tsadc);
- spin_unlock(&tsadc->reg_lock);
+ spin_unlock_irqrestore(&tsadc->reg_lock, flags);
}
EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);

--
1.8.4.rc3

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