lkml.org 
[lkml]   [2023]   [Sep]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/3] irqchip: renesas-rzg2l: Fix irq storm with edge trigger detection for TINT
On Tue, 19 Sep 2023 17:32:05 +0100,
Biju Das <biju.das.jz@bp.renesas.com> wrote:

[...]

> > So you mean that you *already* lose interrupts across a disable followed by
> > an enable? I'm slightly puzzled...
>
> There is no interrupt lost at all.
>
> Currently this patch addresses 2 issues.
>
> Scenario 1: Extra interrupt when we select TINT source on enable_irq()
>
> Getting an extra interrupt, when client drivers calls enable_irq()
> during probe()/resume(). In this case, the irq handler on the Client
> driver just clear the interrupt status bit.
>
> Issue 2: IRQ storm when we select TINT source on enable_irq()
>
> Here as well, we are getting an extra interrupt, when client drivers
> calls enable_irq() during probe() and this Interrupts getting
> generated infinitely, when the client driver calls disable_irq() in
> irq handler and in in work queue calling enable_irq().

How do you know this is a spurious interrupt? For all you can tell,
you are just consuming an edge. I absolutely don't buy this
workaround, because you have no context that allows you to
discriminate between a real spurious interrupt and a normal interrupt
that lands while the interrupt line was masked.

> Currently we are not loosing interrupts, but we are getting additional
> Interrupt(phantom) which is causing the issue.

If you get an interrupt at probe time in the endpoint driver, that's
probably because the device is not in a quiescent state when the
interrupt is requested. And it is probably this that needs addressing.

M.

--
Without deviation from the norm, progress is not possible.

\
 
 \ /
  Last update: 2023-09-19 19:13    [W:0.088 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site