Date:   Mon, 29 Nov 2021 19:08:13 +0000
From:   Mark Brown <broonie@kernel.org>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Tang Bin <tangbin@cmss.chinamobile.com>,
        cezary.rojewski@intel.com, liam.r.girdwood@linux.intel.com,
        yang.jie@linux.intel.com, perex@perex.cz, tiwai@suse.com,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ASoC: Intel: atom: Remove redundant check to simplify
 the code
Message-ID: <YaUlHRHu4G0EMHE5@sirena.org.uk>
References: <20211125075028.8500-1-tangbin@cmss.chinamobile.com>
 <3ca07ce3-6d5c-20cc-8992-4700490ea472@linux.intel.com>
 <YaUJ2EfU6kYFfjWn@sirena.org.uk>
 <YaUjfFNA6IScPCY9@smile.fi.intel.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="k8dI/ervwTv43JI3"
Content-Disposition: inline
In-Reply-To: <YaUjfFNA6IScPCY9@smile.fi.intel.com>
Precedence: bulk


--k8dI/ervwTv43JI3
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Mon, Nov 29, 2021 at 09:01:16PM +0200, Andy Shevchenko wrote:
> On Mon, Nov 29, 2021 at 05:11:52PM +0000, Mark Brown wrote:

> > Zero is (or was, people were working on changing it partly due to
> > confusion and partly due to moving to newer infrastructure which
> > doesn't use it) a valid IRQ on some architectures.  x86 wasn't one of
> > those though, at least AFAIR.

> I guess it's about x86, but the API returns Linux virtual IRQ and 0 shouldn't
> be among them (hardware IRQ != Linux virtual IRQ). Legacy x86 used 1:1 mapping
> for ISA IRQs (lower 16) among which the Timer IRQ is 0. I believe that timer
> code does not use any of those APIs (it most likely and IIRC has it hardcoded).

Right, the virtual IRQs are the newer stuff.  32 bit arm was another
platform that had 0 as a valid IRQ for similar reasons, I don't know if
any of the platforms are still affected though and I'm going to go out
on a limb and say they're not using platform_irq_get_optional().

--k8dI/ervwTv43JI3
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmGlJR0ACgkQJNaLcl1U
h9B2PQf/WYlsV4CNaOQAoyzsD41CNi8U8xmJLZ8eWTAX5tT8wDWiaeekfJbSNMX+
Ebrezn/oQWkJWO72I8cU1ukfBoe5dZh7/UhWzWZwB4zqVdzAqEjjbluAeT3kQw1t
EoNAmG0r+yqlglNOsW6I//4X2XV5hwrxxcFNOTt1LEefeHia1sdPUtXcx5qr8j/w
PKO0jJ385qQb5MzZTemGWFPw/VXSOeA/7fPIetF6MH/nyqodaAg2XJDg/maN9drb
NNms/8YRZzWQsREsDCMLI+kBy3gMwWfMot6aAbEuf37hK1rPWTsMfkxf7OVXoreg
HRMZ/9WKuV4NM/Owm3Lbl3CDj+FqrA==
=1J2J
-----END PGP SIGNATURE-----

--k8dI/ervwTv43JI3--