Subject: Re: Legacy PCI interrupt support in PCIe host driver
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Marc Zyngier <marc.zyngier@arm.com>,
        Jason Cooper <jason@lakedaemon.net>,
        linux-pci <linux-pci@vger.kernel.org>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Thibaud Cornic <thibaud_cornic@sigmadesigns.com>,
        Phuong Nguyen <phuong_nguyen@sigmadesigns.com>,
        Robin Murphy <robin.murphy@arm.com>, Liviu Dudau <liviu.dudau@arm.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>,
        Rob Herring <robh@kernel.org>
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 <8443b350-6aa6-75f8-af48-892c722fc2d9@free.fr>
 <alpine.DEB.2.20.1703161843420.3586@nanos>
From: Mason <slash.tmp@free.fr>
Message-ID: <4e54c5f9-7cc1-cfab-592d-a87795147020@free.fr>
Date: Thu, 16 Mar 2017 20:13:15 +0100
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On 16/03/2017 18:47, Thomas Gleixner wrote:
> On Thu, 16 Mar 2017, Mason wrote:
>> I guess if two interrupts fire at the same time, we'll just take two
>> separate exceptions?
> 
> Wrong guess. That might work with level interrupts, but with other types
> nothing will raise another exception. Sharing interrupts on edge types is a
> stupid idea, but hardware folks insist on implementing stupid ideas.

When you say "That might work with level interrupts",
what is "that" ?

In my case,

	interrupt-map = <0 0 0 1 &irq0 54 IRQ_TYPE_LEVEL_HIGH>;
	interrupts = <54 IRQ_TYPE_LEVEL_HIGH>;

Both ISRs expect LEVEL_HIGH. In fact, doesn't request_irq
return an error if the triggers are different?

Regards.