diff options
| author | Marc Zyngier <maz@kernel.org> | 2022-02-24 13:12:25 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-03-01 13:06:25 +0300 |
| commit | a6aca2f460e203781dc41391913cc5b54f4bc0ce (patch) | |
| tree | b7e3d153e1e7feafbbf01506f0439cb1e8556354 /drivers/irqchip | |
| parent | d494d088ac44b9cf561362a7856fa20b656be64f (diff) | |
| download | linux-a6aca2f460e203781dc41391913cc5b54f4bc0ce.tar.xz | |
irqchip/qcom-pdc: Fix broken locking
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
Diffstat (limited to 'drivers/irqchip')
| -rw-r--r-- | drivers/irqchip/qcom-pdc.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c index 837ca6998f6a..0cd20ddfae2a 100644 --- a/drivers/irqchip/qcom-pdc.c +++ b/drivers/irqchip/qcom-pdc.c @@ -55,17 +55,18 @@ static u32 pdc_reg_read(int reg, u32 i) 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) |