Subject: Re: [PATCH] opal-elog: Fix opal-elog interrupt handler

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Sat, 04 Jul 2015 12:04:00 +0530

Alistair Popple <[email-masked]> writes:

> The conversion of opal events to a proper irqchip means that handlers
> are called until the relevant opal event has been cleared by
> processing it. Events that queue work should therefore use a threaded
> handler to mask the event until processing is complete.
>
> Signed-off-by: Alistair Popple <[email-masked]>

Tested-by: Aneesh Kumar K.V <[email-masked]>

> ---
>  arch/powerpc/platforms/powernv/opal-elog.c | 16 +++++-----------
>  1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/opal-elog.c b/arch/powerpc/platforms/powernv/opal-elog.c
> index 4949ef0..37f959b 100644
> --- a/arch/powerpc/platforms/powernv/opal-elog.c
> +++ b/arch/powerpc/platforms/powernv/opal-elog.c
> @@ -237,7 +237,7 @@ static struct elog_obj *create_elog_obj(uint64_t id, size_t size, uint64_t type)
>  	return elog;
>  }
>
> -static void elog_work_fn(struct work_struct *work)
> +static irqreturn_t elog_event(int irq, void *data)
>  {
>  	__be64 size;
>  	__be64 id;
> @@ -251,7 +251,7 @@ static void elog_work_fn(struct work_struct *work)
>  	rc = opal_get_elog_size(&id, &size, &type);
>  	if (rc != OPAL_SUCCESS) {
>  		pr_err("ELOG: OPAL log info read failed\n");
> -		return;
> +		return IRQ_HANDLED;
>  	}
>
>  	elog_size = be64_to_cpu(size);
> @@ -270,16 +270,10 @@ static void elog_work_fn(struct work_struct *work)
>  	 * entries.
>  	 */
>  	if (kset_find_obj(elog_kset, name))
> -		return;
> +		return IRQ_HANDLED;
>
>  	create_elog_obj(log_id, elog_size, elog_type);
> -}
> -
> -static DECLARE_WORK(elog_work, elog_work_fn);
>
> -static irqreturn_t elog_event(int irq, void *data)
> -{
> -	schedule_work(&elog_work);
>  	return IRQ_HANDLED;
>  }
>
> @@ -304,8 +298,8 @@ int __init opal_elog_init(void)
>  		return irq;
>  	}
>
> -	rc = request_irq(irq, elog_event,
> -			IRQ_TYPE_LEVEL_HIGH, "opal-elog", NULL);
> +	rc = request_threaded_irq(irq, NULL, elog_event,
> +			IRQF_TRIGGER_HIGH | IRQF_ONESHOT, "opal-elog", NULL);
>  	if (rc) {
>  		pr_err("%s: Can't request OPAL event irq (%d)\n",
>  		       __func__, rc);
> -- 
> 2.1.4