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Date: Sat, 13 Apr 2024 16:56:36 +0100
From: Jonathan Cameron <jic23@kernel.org>
To: Nuno =?UTF-8?B?U8Oh?= <noname.nuno@gmail.com>
Cc: Markus Burri <markus.burri@mt.com>, linux-kernel@vger.kernel.org,
 Lars-Peter Clausen <lars@metafoo.de>, Michael Hennerich
 <Michael.Hennerich@analog.com>, linux-iio@vger.kernel.org, Nuno Sa
 <nuno.sa@analog.com>
Subject: Re: [PATCH v1] iio: adc: ad_sigma_delta: Clear pending interrupts
 before enable
Message-ID: <20240413165636.4fa8eb60@jic23-huawei>
In-Reply-To: <b6c6700d924916dd09afd2878321a7c87b8e922d.camel@gmail.com>
References: <20240404175126.110208-1-markus.burri@mt.com>
	<20240406171728.16170b48@jic23-huawei>
	<b6c6700d924916dd09afd2878321a7c87b8e922d.camel@gmail.com>
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On Mon, 08 Apr 2024 10:31:21 +0200
Nuno S=C3=A1 <noname.nuno@gmail.com> wrote:

> On Sat, 2024-04-06 at 17:17 +0100, Jonathan Cameron wrote:
> > On Thu,=C2=A0 4 Apr 2024 19:51:26 +0200
> > Markus Burri <markus.burri@mt.com> wrote:
> >=20
> > Hi Markus,
> >=20
> >  =20
> > > For device will enable and disable irq contiously like AD7195,
> > > it use DOUT/RDY pin for both SPI transfer and data ready.
> > > It will disable irq during SPI transfer, and re-eanble irq after SPI
> > > transfer.
> > > That may cause irq status bit set to 1 during spi transfer. =20
> >=20
> > Superficially that sounds like it might be an irq driver bug to me...
> > Or just possibly an irq chip doing lazy disabling? =20
>=20
> Yes, this sounds odd as we are already explicitly disabling lazy disablin=
g:
>=20
> https://elixir.bootlin.com/linux/latest/source/drivers/iio/adc/ad_sigma_d=
elta.c#L589

Markus, can you confirm you are running no a kernel with that line present?
Maybe this is just an old kernel not having the fix?

>=20
> >  =20
> > >=20
> > > When the active condition has been detected, the corresponding bit
> > > remains set until cleared by software. Status flags are cleared
> > > by writing a 1 to the corresponding bit position.
> > >=20
> > > Signed-off-by: Markus Burri <markus.burri@mt.com> =20
> >=20
> > I'll need an appropriate ADI ack for this one.
> >  =20
>=20
> Yeah, I wanted to reply to this one Friday but then completely forgot. I =
can't
> really ack this one. I would need some insights from someone with more co=
re IRQ
> knowledge. But...
>=20
> > It seems highly unusual to be calling a generic irqchip related functio=
n in a
> > driver (there are no other such users).=C2=A0 So this seems unlikely to=
 be
> > the right fix for this particular problem.
> >  =20
>=20
> Yes, and this (I think) would not even fix (if a fix is needed) this for =
all
> irqchips which to me already sounds not the way to go.
>=20
> - Nuno S=C3=A1
> >  =20