linux-kernel - Re: [PATCH 03/12] drivers: irqchip: pdc: Do not toggle IRQ

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Date:   Fri, 15 Nov 2019 10:49:11 -0800
From:   Stephen Boyd <swboyd@...omium.org>
To:     Lina Iyer <ilina@...eaurora.org>, bjorn.andersson@...aro.org,
        linus.walleij@...aro.org, maz@...nel.org
Cc:     evgreen@...omium.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, mkshah@...eaurora.org,
        linux-gpio@...r.kernel.org, agross@...nel.org,
        dianders@...omium.org, Lina Iyer <ilina@...eaurora.org>
Subject: Re: [PATCH 03/12] drivers: irqchip: pdc: Do not toggle IRQ_ENABLE during mask/unmask

Quoting Lina Iyer (2019-11-14 10:35:12)
> When an interrupt is to be serviced, the convention is to mask the
> interrupt at the chip and unmask after servicing the interrupt. Enabling
> and disabling the interrupt at the PDC irqchip causes an interrupt storm
> due to the way dual edge interrupts are handled in hardware.
> 
> Skip configuring the PDC when the IRQ is masked and unmasked, instead
> use the irq_enable/irq_disable callbacks to toggle the IRQ_ENABLE
> register at the PDC. The PDC's IRQ_ENABLE register is only used during
> the monitoring mode when the system is asleep and is not needed for
> active mode detection.
> 
> Signed-off-by: Lina Iyer <ilina@...eaurora.org>
> ---

Reviewed-by: Stephen Boyd <swboyd@...omium.org>