netdev - Re: [PATCH] net: phylink: dsa: mv88e6xxx: Revise irq setup ordering

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Message-ID: <20190204224728.GF3397@lunn.ch>
Date:   Mon, 4 Feb 2019 23:47:28 +0100
From:   Andrew Lunn <andrew@...n.ch>
To:     John David Anglin <dave.anglin@...l.net>
Cc:     Russell King <linux@....linux.org.uk>,
        Vivien Didelot <vivien.didelot@...oirfairelinux.com>,
        Florian Fainelli <f.fainelli@...il.com>, netdev@...r.kernel.org
Subject: Re: [PATCH] net: phylink: dsa: mv88e6xxx: Revise irq setup ordering

On Mon, Feb 04, 2019 at 04:38:53PM -0500, John David Anglin wrote:
> On 2019-02-04 3:19 p.m., Andrew Lunn wrote:
> > The IRQ core would do this if it was needed.
> >
> > How many other irq thread work functions can you point to which do
> > something similar?
> This is comment for handle_edge_irq:
> 
> /**
>  *    handle_edge_irq - edge type IRQ handler
>  *    @desc:    the interrupt description structure for this irq
>  *
>  *    Interrupt occures on the falling and/or rising edge of a hardware
>  *    signal. The occurrence is latched into the irq controller hardware
>  *    and must be acked in order to be reenabled. After the ack another
>  *    interrupt can happen on the same source even before the first one
>  *    is handled by the associated event handler. If this happens it
>  *    might be necessary to disable (mask) the interrupt depending on the
>  *    controller hardware. This requires to reenable the interrupt inside
>  *    of the loop which handles the interrupts which have arrived while
>  *    the handler was running. If all pending interrupts are handled, the
>  *    loop is left.
>  */
> 
> As can be seen, the above comment suggests that it may be necessary to
> disable (mask) interrupt
> as I proposed.

Hi Dave

This comment is describing what handle_edge_irq() actually does. Read
the code. It does not say anything about that the handling thread
function should do.

	 Andrew