From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier-5wv7dgnIgG8@public.gmane.org>
Subject: Re: [PATCH V6 2/9] genirq: Look-up trigger type if not specified by
 caller
Date: Mon, 13 Jun 2016 11:42:49 +0100
Message-ID: <575E8E29.3090808@arm.com>
References: <1465312354-27778-1-git-send-email-jonathanh@nvidia.com>
 <1465312354-27778-3-git-send-email-jonathanh@nvidia.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Return-path: <linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
In-Reply-To: <1465312354-27778-3-git-send-email-jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
To: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>, Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, Jason Cooper <jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org>
Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>, Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>, Ian Campbell <ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>, Kumar Gala <galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>, Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>, Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Kevin Hilman <khilman-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Geert Uytterhoeven <geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org>, Grygorii Strashko <grygorii.strashko-l0cyMroinI0@public.gmane.org>, Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>, Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
List-Id: linux-tegra@vger.kernel.org

On 07/06/16 16:12, Jon Hunter wrote:
> For some devices the IRQ trigger type for a device is read from
> firmware, such as device-tree. The IRQ trigger type is typically read
> when the mapping for IRQ is created, which is before the IRQ is
> requested. Hence, the IRQ trigger type is programmed when mapping the
> IRQ and not when requesting the IRQ.
> 
> Although this works for most cases, in order to support IRQ chips which
> require runtime power management, which may not be accessible prior
> to requesting the IRQ, it is desirable to look-up the IRQ trigger type
> when it is requested. Therefore, if the IRQ trigger type is not
> specified when __setup_irq() is called, look-up the saved IRQ trigger
> type. This will allow us to defer the programming of the trigger type
> from when the IRQ is mapped to when it is actually requested.
> 
> Signed-off-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> Reviewed-by: Marc Zyngier <marc.zyngier-5wv7dgnIgG8@public.gmane.org>
> ---
>  kernel/irq/manage.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index ef0bc02c3a70..eaedeb74b49d 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -1117,6 +1117,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
>  	new->irq = irq;
>  
>  	/*
> +	 * If the trigger type is not specified by the caller,
> +	 * then use the default for this interrupt.
> +	 */
> +	if (!(new->flags & IRQF_TRIGGER_MASK))
> +		new->flags |= irqd_get_trigger_type(&desc->irq_data);
> +
> +	/*
>  	 * Check whether the interrupt nests into another interrupt
>  	 * thread.
>  	 */
> 

I've added the following patch to the queue, in order to deal with
percpu interrupts that were not handled by this patch:

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index f8fd1fb..00cfc85 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1751,7 +1751,14 @@ void enable_percpu_irq(unsigned int irq, unsigned int type)
 	if (!desc)
 		return;
 
+	/*
+	 * If the trigger type is not specified by the caller, then
+	 * use the default for this interrupt.
+	 */
 	type &= IRQ_TYPE_SENSE_MASK;
+	if (type == IRQ_TYPE_NONE)
+		type = irqd_get_trigger_type(&desc->irq_data);
+
 	if (type != IRQ_TYPE_NONE) {
 		int ret;
 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...