linux-kernel - Re: [PATCH v2 3/3] genirq: Do not test disabled IRQs with DEBUG

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Message-ID: <CAJKOXPfEpLN9jS11WW367Na3Ukfi8p3urKDcJoafg9dHuCDSUA@mail.gmail.com>
Date:   Tue, 16 Jun 2020 12:11:17 +0200
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     Mark Brown <broonie@...nel.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Vladimir Oltean <vladimir.oltean@....com>,
        linux-spi@...r.kernel.org,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Marc Kleine-Budde <mkl@...gutronix.de>,
        Wolfram Sang <wsa@...nel.org>, kernel@...gutronix.de
Subject: Re: [PATCH v2 3/3] genirq: Do not test disabled IRQs with DEBUG_SHIRQ

On Mon, Jun 15, 2020 at 01:08:44PM +0100, Mark Brown wrote:
> On Mon, Jun 15, 2020 at 10:07:19AM +0200, Krzysztof Kozlowski wrote:
> > Testing events during freeing of disabled shared interrupts
> > (CONFIG_DEBUG_SHIRQ) leads to false positives.  The driver disabled
> > interrupts on purpose to be sure that they will not fire during device
> > removal.
>
> Surely the whole issue with shared IRQs that's being tested for here is
> that when the interrupt is shared some other device connected to the
> same interrupt line may trigger an interrupt regardless of what's going
> on with this device?

Yes. However if that device disabled the interrupt, it should not be
fired for other users. In such case the testing does not point to a
real issue.

Anyway, this patch is not necessary with my v3 approach to SPI shared
interrupts issue.

Best regards,
Krzysztof