Re: [PATCH 4/5] irqchip/qcom-pdc: Fix broken locking

Maulik Shah (mkshah)
2022-02-28T19:49:11Z

Hi,

On 2/24/2022 3:42 PM, Marc Zyngier wrote:
> 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>

Thanks,
Maulik
> ---
> drivers/irqchip/qcom-pdc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
>