pdc_enable_intr() serves as a primitive to qcom_pdc_gic_{en,dis}able,
and has a raw spinlock for mutual exclusion, which is uses with
interruptible primitives.
This means that this critical section can itself be interrupted.
Should the interrupt also be a PDC interrupt, and the endpoint driver
perform an irq_disable() on that interrupt, we end-up in a deadlock.
Fix this by using the irqsave/irqrestore variants of the locking
primitives.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Maulik Shah <quic_mkshah@quicinc.com>
Link: https://lore.kernel.org/r/20220224101226.88373-5-maz@kernel.org
static void pdc_enable_intr(struct irq_data *d, bool on)
{
int pin_out = d->hwirq;
+ unsigned long flags;
u32 index, mask;
u32 enable;
index = pin_out / 32;
mask = pin_out % 32;
- raw_spin_lock(&pdc_lock);
+ raw_spin_lock_irqsave(&pdc_lock, flags);
enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
- raw_spin_unlock(&pdc_lock);
+ raw_spin_unlock_irqrestore(&pdc_lock, flags);
}
static void qcom_pdc_gic_disable(struct irq_data *d)