From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH 1/2] arm64: dts: allwinner: Olimex A64-OLinuXino: enable eMMC. Date: Sat, 29 Sep 2018 17:47:54 +0200 Message-ID: <20180929154754.abz3byvrufvnf4dq@flea> References: <20180919141815.18737-1-rodrigo@tjader.xyz> <20180921142811.h5jraemk565alh3i@flea> <20180925090139.qbu6tqav5oth7zkw@flea> <20180927081711.llmwnvpu73loe5iv@flea> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="mgswahgbsrhmlk2r" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Rodrigo =?utf-8?B?RXh0ZXJja8O2dHRlciBUasOkZGVy?= Cc: wens@csie.org, robh+dt@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org --mgswahgbsrhmlk2r Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 27, 2018 at 11:49:20AM -0300, Rodrigo Exterck=F6tter Tj=E4der w= rote: > On Thu, Sep 27, 2018 at 5:17 AM Maxime Ripard = wrote: > > > > On Tue, Sep 25, 2018 at 02:47:59PM -0300, Rodrigo Exterck=F6tter Tj=E4d= er wrote: > > > On Tue, Sep 25, 2018 at 6:01 AM Maxime Ripard wrote: > > > > We can't really do that, unfortunately. If the device tree name was= to > > > > change for a given board, we'd break all the build systems, boot > > > > scripts and distros out there. > > > > > > What if we keep the device tree for the version without WiFi and eMMC > > > with the current name and create new device trees for the other two > > > versions? > > > > Wifi and Bluetooth should be dealt with with overlays in this case, > > and since the eMMC is already enabled, then there's nothing to do, I > > guess. >=20 > It's WiFi that is already enabled, not eMMC. Only one of the three > variants has WiFi. Ah, right, sorry. In the board that doesn't have an emmc, are the pins usable for something else? > We can't even remove a node from a device tree? Removing the WiFi node > from the current tree would make it correspond to the variant with the > least features. Not really. How pissed would you be if you were a user, had wifi running on your board, you upgrade your kernel, and then it's just gone? :) > About device tree overlays, I read overlay-notes.txt, but I went > looking for an example with "git grep /plugin/ arch" and it came > empty. Is this approach not used for other boards? It is, it's simply not stored in the kernel, but through other third party repos. > Does the overlay approach make the device available at boot time? That > is important for a storage device such as eMMC. >=20 > I went with the separate dts approach because that's what I saw was > done for other similar cases, like Pine64 and Pine64+, OLinuXino-LIME2 > and its variant with eMMC, among others. Yeah, but in all these cases, it was done from day one, not after the facts. Maxime --=20 Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --mgswahgbsrhmlk2r Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE0VqZU19dR2zEVaqr0rTAlCFNr3QFAluvnqkACgkQ0rTAlCFN r3RX6w/+IqyREh6KVQvgVbNdXP8BEG4F0cdooVJRHaF/D463kTMkm/F6GAel+AQi 7yY9NRdfrypX3U5ua1n+fdGkgX1vrB05frX9h2RuV05GzT34wPK3J6dAk4G93nSQ gp5nvnbJqZsvjq26DRG79QL6GVLLC7eN/K9YyieGIAZx/vP+R+MWFHlNXw/HBU4k P7ef9+2Ll9g5AiFsWMu3SLxHeSOVX08H4TbWAVG7k7U4jHhJ8bCPf5J+5TsJR2t5 Q8X0L87Q4Y0XilKFrH7ObqNcbb0a8GY/0nim2seF0V5+Cp5HdQwoeu9FSz27CE3g 3PPVCXQHbgreB4knBbiVCDHRuJAgNEhPQ5cE9LPfNlvkravCVmabZjogOdJxKt5O 8z7GKeXI7IThzV5KyXuKEoVVOpxO9UAn9NQKztLgoF6lQqy/un0diDtGLTNzr7uM pI/mKOvxFHbI1l/8oUIp2sQnMApbyFve+K++zwBxjdpk8mEcHHJLwz/rCp8MEUdl NIjSUSbxgld0k3wmc/TrU/Qsmj5qZO8Bgv7ix9RZQvCNpocg40NhQJ/PQkTUemqs jWtiUtfBWh6YSi0jYpdDzkv+w0E9w2VB5GB1iBR1PJXSWBI3UjrGXlW/BFFRKEwU ifJEGdcMyeuyCN22dvAF8u3pP0zojX4HkCc8Gq+xPOSYnQTVGUE= =3kOj -----END PGP SIGNATURE----- --mgswahgbsrhmlk2r--