Subject: Re: [PATCH 08/15] genirq: Add runtime power management support for
 IRQ chips
To: Thomas Gleixner <tglx@linutronix.de>,
        Linus Walleij <linus.walleij@linaro.org>
References: <1458224359-32665-1-git-send-email-jonathanh@nvidia.com>
 <1458224359-32665-9-git-send-email-jonathanh@nvidia.com>
 <alpine.DEB.2.11.1603171556020.3978@nanos>
CC: Jason Cooper <jason@lakedaemon.net>, Marc Zyngier <marc.zyngier@arm.com>,
        =?UTF-8?Q?Beno=c3=aet_Cousson?= <bcousson@baylibre.com>,
        Tony Lindgren <tony@atomide.com>, Rob Herring <robh+dt@kernel.org>,
        Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>,
        Ian Campbell <ijc+devicetree@hellion.org.uk>,
        Kumar Gala <galak@codeaurora.org>,
        "Stephen Warren" <swarren@wwwdotorg.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Kevin Hilman <khilman@kernel.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Grygorii Strashko <grygorii.strashko@ti.com>,
        Lars-Peter Clausen <lars@metafoo.de>, <linux-tegra@vger.kernel.org>,
        <linux-omap@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
From: Jon Hunter <jonathanh@nvidia.com>
Message-ID: <56EAD140.3090709@nvidia.com>
Date: Thu, 17 Mar 2016 15:46:08 +0000
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On 17/03/16 15:02, Thomas Gleixner wrote:
> On Thu, 17 Mar 2016, Jon Hunter wrote:
>>  /**
>>   * struct irq_chip - hardware interrupt chip descriptor
>>   *
>> + * @parent:		pointer to associated device
> 
> That's really a bad name. parent suggests that this is a parent interrupt chip
> and your explanation sucks as well. What's an associated device? Network card? 

Linus, can you re-iterate your concerns here about just using 'dev' for
the name?

>>  #include <linux/irqdesc.h>
>>  #include <linux/kernel_stat.h>
>> +#include <linux/pm_runtime.h>
>>  
>>  #ifdef CONFIG_SPARSE_IRQ
>>  # define IRQ_BITMAP_BITS	(NR_IRQS + 8196)
>> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
>> index b2a93a37f772..65878e7c7c82 100644
>> --- a/kernel/irq/manage.c
>> +++ b/kernel/irq/manage.c
>> @@ -1114,6 +1114,10 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
>>  	if (!try_module_get(desc->owner))
>>  		return -ENODEV;
>>  
>> +	ret = irq_chip_pm_get(&desc->irq_data);
>> +	if (ret < 0)
>> +		goto out_mput;
> 
> So this call nests inside the chip_bus_lock() region. Is that intentional?

Hmm ... I was trying to simplify the call paths, but yes I think it
would be safer to move outside. Ok, will fix that.

Cheers
Jon