Re: [PATCH v3 1/2] thermal: rcar_gen3_thermal: fix interrupt type

From: Daniel Lezcano
Date: Tue Apr 23 2019 - 18:35:34 EST


On 23/04/2019 16:14, Jiada Wang wrote:
> Currently IRQF_SHARED type interrupt line is allocated, but it
> is not appropriate, as the interrupt line isn't shared between
> different devices, instead IRQF_ONESHOT is the proper type.
>
> By changing interrupt type to IRQF_ONESHOT, now irq handler is
> no longer needed, as clear of interrupt status can be done in
> threaded interrupt context.
>
> Because IRQF_ONESHOT type interrupt line is kept disabled until
> the threaded handler has been run, so there is no need to protect
> read/write of REG_GEN3_IRQSTR with lock.
>
> Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>

Fixes: 7d4b269776ec6 ("enable hardware interrupts for trip points")
Suggested-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>





> ---
> drivers/thermal/rcar_gen3_thermal.c | 34 +++++------------------------
> 1 file changed, 6 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
> index 88fa41cf16e8..ebbaef5a3cf1 100644
> --- a/drivers/thermal/rcar_gen3_thermal.c
> +++ b/drivers/thermal/rcar_gen3_thermal.c
> @@ -231,39 +231,17 @@ static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
> static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
> {
> struct rcar_gen3_thermal_priv *priv = data;
> + int i;
> u32 status;
> - int i, ret = IRQ_HANDLED;
>
> - spin_lock(&priv->lock);
> for (i = 0; i < priv->num_tscs; i++) {
> status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
> rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
> if (status)
> - ret = IRQ_WAKE_THREAD;
> + thermal_zone_device_update(priv->tscs[i]->zone,
> + THERMAL_EVENT_UNSPECIFIED);
> }
>
> - if (ret == IRQ_WAKE_THREAD)
> - rcar_thermal_irq_set(priv, false);
> -
> - spin_unlock(&priv->lock);
> -
> - return ret;
> -}
> -
> -static irqreturn_t rcar_gen3_thermal_irq_thread(int irq, void *data)
> -{
> - struct rcar_gen3_thermal_priv *priv = data;
> - unsigned long flags;
> - int i;
> -
> - for (i = 0; i < priv->num_tscs; i++)
> - thermal_zone_device_update(priv->tscs[i]->zone,
> - THERMAL_EVENT_UNSPECIFIED);
> -
> - spin_lock_irqsave(&priv->lock, flags);
> - rcar_thermal_irq_set(priv, true);
> - spin_unlock_irqrestore(&priv->lock, flags);
> -
> return IRQ_HANDLED;
> }
>
> @@ -390,9 +368,9 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
> if (!irqname)
> return -ENOMEM;
>
> - ret = devm_request_threaded_irq(dev, irq, rcar_gen3_thermal_irq,
> - rcar_gen3_thermal_irq_thread,
> - IRQF_SHARED, irqname, priv);
> + ret = devm_request_threaded_irq(dev, irq, NULL,
> + rcar_gen3_thermal_irq,
> + IRQF_ONESHOT, irqname, priv);
> if (ret)
> return ret;
> }
>


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