Messages in this thread | | | From | Alexey Khoroshilov <> | Subject | Deadlock in grgpio_irq_unmap() | Date | Sun, 2 Aug 2015 23:15:22 +0700 |
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Dear colleagus,
grgpio_irq_unmap() code looks quite suspicious regarding usage of priv->bgc.lock spinlock.
It locks the spinlock in line 310: spin_lock_irqsave(&priv->bgc.lock, flags); and then it can call grgpio_set_imask() in line 317: grgpio_set_imask(priv, i, 0);
But grgpio_set_imask() unconditionally locks the spinlock by itself.
static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset, int val) { struct bgpio_chip *bgc = &priv->bgc; unsigned long mask = bgc->pin2mask(bgc, offset); unsigned long flags;
spin_lock_irqsave(&bgc->lock, flags);
if (val) priv->imask |= mask; else priv->imask &= ~mask; bgc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask);
spin_unlock_irqrestore(&bgc->lock, flags); }
So, it looks like unavoidable deadlock here.
Found by Linux Driver Verification project (linuxtesting.org).
-- Alexey Khoroshilov Linux Verification Center, ISPRAS web: http://linuxtesting.org
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