From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH] drm: Rationalize DRM_MIPI_DSI inclusion in Kconfig Date: Fri, 17 Aug 2018 11:39:13 +0200 Message-ID: <20180817093913.GA31981@ulmo> References: <20180816185414.104152-1-sean@poorly.run> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2008474433==" Return-path: Received: from mail-wm0-x244.google.com (mail-wm0-x244.google.com [IPv6:2a00:1450:400c:c09::244]) by gabe.freedesktop.org (Postfix) with ESMTPS id B33AD6E5D1 for ; Fri, 17 Aug 2018 09:39:16 +0000 (UTC) Received: by mail-wm0-x244.google.com with SMTP id l2-v6so984984wme.1 for ; Fri, 17 Aug 2018 02:39:16 -0700 (PDT) In-Reply-To: <20180816185414.104152-1-sean@poorly.run> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Sean Paul Cc: Jani Nikula , Sean Paul , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============2008474433== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="y0ulUmNC+osPPQO6" Content-Disposition: inline --y0ulUmNC+osPPQO6 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 16, 2018 at 02:54:14PM -0400, Sean Paul wrote: > From: Sean Paul >=20 > DRM_MIPI_DSI is included via both "select" and "depends on", this is > trouble waiting to happen since this will result in different behavior > depending on which is used. >=20 > This patch resolves the problem by: > - Converting all inclusion to "select" since DRM_MIPI_DSI is not a menu > item. > - Remove "depends on DRM" since "select"ing DRM_MIPI_DSI won't include > DRM anyways, so this is misleading. The reason behind the decision to have both select and depends on for this was, if I recall correctly, so that a driver would select the symbol if it implemented (i.e. "provided") a DSI controller and panel drivers (or bridge drivers for that matter) would depend on the symbol to specify that they want to "consume" a DSI controller. That way the DSI panels and bridges can't be selected unless there is a driver that provides a DSI controller. If there's no driver that provides a DSI controller, there's no use in enabling any panels that need one. Granted, in retrospect this seems somewhat over-engineered, but the reason why it works is because thy symbol is not user-visible. That's one of the, I think even documented, use-cases where it is safe to use both select and depends. That said, I'm fine with simplifying this, but if we do, I would prefer going all the way and just removing the symbol entirely. It's not like it is a lot of extra infrastructure, at least compared to the rest of the helpers that we already pull in. There are also quite a few drivers that support DSI now, so I think there's more justification for unconditional inclusion than there used to be. Thierry --y0ulUmNC+osPPQO6 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAlt2l74ACgkQ3SOs138+ s6GmhBAAu84wY8x1VZBMX9ixrAAvSNAnURoGAOL4KHGexMNp3KdQ5J6b8ozpR7g3 pFN7H8kiqk9dwUwgp2Zw/OVIuX9DsLsqvSqb5E91r3nJE2VU+MO343nBuyvSGw84 etsHgN2EO1Ndgw4xci4x3uQ/DckebJBVDMCaIAJT03lcLRHeEAJmvFEyqe2Z69Xe KyhHcyv86VigghU+/1lZhz/xLkay54WIaMVsZlVcLPHsvo9GjvpkksWdCeISr3Es 0fOFXhIYewmyZRJ18rIpjI2L73QZim/IMI2e6IPS4QeLDE3J3CWU1YoMM95FCig/ 9b1oMxAy+yDA+Tc2QZymaBd6QY8YP8dE776VJSvJDlQysxMiKXu2sZz49muT2yt/ IeQ9WaR6cVCGukGckInHEW0pwifXo2EzmhUJQfLVNFF6CJG7fH6sl6qJwdi7TGpU K0aRQwQoONhI9mlfl7ou1pRokyP+rcrRthCJlB+oAisIs3odbf5v/VddoLt1sEoG jBs6MhLHnb+j9v85ZhAqIj/6ToiEcRLoObXbGQcP5HdjcETKx8q7tU75Lv1uim0p Q6eKDmNso5sEETcT4/bwIqXxm7yOcGHG+86M860vzx/R/uE8MG4JT3PTWV6fSmwE iwC1udCY7XzH9/Ql8QNy9lx6tQ1Dqbl3grsKauewLV9b6PcJ654= =unWm -----END PGP SIGNATURE----- --y0ulUmNC+osPPQO6-- --===============2008474433== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============2008474433==--