From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH v3 3/5] i2c: mux: pca954x: Add interrupt controller support Date: Fri, 13 Jan 2017 19:54:17 +0100 Message-ID: <20170113185417.GA1449@katana> References: <1483952576-5308-1-git-send-email-preid@electromag.com.au> <1483952576-5308-4-git-send-email-preid@electromag.com.au> <383ee3cb-b452-259f-486f-682ea9526708@axentia.se> <1284b1c8-bb90-fbd9-53a2-0c36f2597b29@electromag.com.au> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2fHTh5uZTiUOsy+g" Return-path: Content-Disposition: inline In-Reply-To: <1284b1c8-bb90-fbd9-53a2-0c36f2597b29-qgqNFa1JUf/o2iN0hyhwsIdd74u8MsAO@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Phil Reid Cc: Peter Rosin , robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --2fHTh5uZTiUOsy+g Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > >BTW, what does client->irq =3D=3D 0 represent? >=20 > This one I'm fairly confident on. Initially I had "client->irq < 0" > Which caused problems with an i2c mux that doesn't have irq's defined in = the dt. >=20 > This commit seems to confirm that. > commit dab472eb931b ("i2c / ACPI: Use 0 to indicate that device does not = have interrupt assigned") In the Linux Kernel, 0 means no irq so one can write: if (!irq) ... There used to be NO_IRQ per arch but this is converted over, although it takes a lot of time... If there is a HW IRQ0, it needs to be remapped. But since we rely on irq_desc these days and not irq numbers, this is easy. At least this was the transition a few years ago, but I don't think something essential has changed. Please enlighten me, if so. Regards, Wolfram --2fHTh5uZTiUOsy+g Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJYeSJZAAoJEBQN5MwUoCm2kEAP/iDnVBMuXXzptnBfHv2EGTJd EEqpMeIuk6Dcm7UJQh2SrfSKK6H3gFhQGxocCtiF4EPyDczLTDolMdlDqoBO1xHu 3WODCgDzrMwx3KQgtVtAfqWSLDP5nHc6RKh5K/alqd/8CWkyU8O1s+EdzRgkbdWB 60Lwvlp9RmtqMVrC82Vd804v4v3TI1sCU8adr8gKvNEMx2VySl6osbBwhGMeY8W3 769ByLZcdLU6uWjzDQveKVJsiszH1DHqzCeCSMsLvqTm0nldMH0shnXVy23+dx+R iUY+dirMvMhJiEQMISYJsbKMsHgin+WCr0Wuc1KgTNcjF4Yb3Vicl395KoWsvmMV sbu7k6Nc4ATMB6RyoortgZ8hURe2Dhc6Qqtu4lLYNWiv5wVmuYDaE5bL3ZJgVSRi eYGDTOaj5fDL2+yzDoqKe3HczyUU5i2lH+Q3KL8t5EiY+nNd6iHOhnENUdrw2xQp 36xJ3W5rzmedNNN1fHHagQNTvJ15btqOorp3B1nzOTUBg9P+QZgXCEIqeK+lJ4B4 mTlsgtPYLtalF6fj8LUPrpposmTxEsDEq2mC+18ao0iCD/6IEVDBgZqdIf8whi2N FOXJ2ZgU4VIzsznZ3bV0PkCL/i7ZJVnz5eNJsOsvshtbPywSPSqphLIwy3FTHCzP dqX7X55W65XGlW8TSmFE =UiFk -----END PGP SIGNATURE----- --2fHTh5uZTiUOsy+g-- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html