From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Anholt Subject: RE: [PATCH] drm/vc4: Enable the DSI module and link before other enables. Date: Thu, 21 Jun 2018 16:19:24 -0700 Message-ID: <87a7rnenib.fsf@anholt.net> References: <20180604194437.13790-1-eric@anholt.net> <20180605082532eucas1p21328ec5bea7d588c81480829f862bdfd~1NhnMydDJ0562405624eucas1p2l@eucas1p2.samsung.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0098260508==" Return-path: Received: from anholt.net (anholt.net [50.246.234.109]) by gabe.freedesktop.org (Postfix) with ESMTP id CFF896E86E for ; Thu, 21 Jun 2018 23:19:27 +0000 (UTC) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Kevin Quigley , Andrzej Hajda , "dri-devel@lists.freedesktop.org" Cc: Boris Brezillon , "linux-kernel@vger.kernel.org" , James Hughes List-Id: dri-devel@lists.freedesktop.org --===============0098260508== Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" --=-=-= Content-Type: text/plain Kevin Quigley writes: > Hi, > > When we talk about control bus enable and video transfer enable for > DSI, there is a mode in which control commands can be sent, > interleaved with the video. This is often done at the end-of-frame > and/or end of line. I've seen this handled in some other DSI device > drivers. In these cases, the driver has to look at the frame timing > in the video and carefully select the number of control bytes which > can be sent during the blanking periods. The number of bytes which > can be sent, is very much dependant on the panel-size and clock > frequencies... (which determines the blanking time). I'm not sure how > widely this is a feature in the DSI encoder HW, and/or implemented > purely in the drivers. That scheduling is done by the VC4 DSI encoder. > To conclude: I think that DSI encoder devices need to be able to > support sending control data (LPDA) - concurrently with video frames. I believe that should work already. --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE/JuuFDWp9/ZkuCBXtdYpNtH8nugFAlssMnwACgkQtdYpNtH8 nuj6XhAAgldBul9TX+OY/OhzeAsWa+81VWWIec9ruWi5He5U4/UaCRIcr0/wKhop U3eAYS4E0X8OTcC+s/RqaVHRcmHfTOyoR23OXF2onfyvjibtYfapJ2XJUuGzPpLx inBoU0XvgONM7LyzkaxaAJ/Y40dQ5+vgOLZEy18W0Mu5QFUHvGu7mqSaI3Fg1LMh C3HCUJQKZMUuIwFaBfokZ1hPy7tq8SYnb6V5y3QjDntOF+4HYIYUfCZOejHQNw9M LFxyqf1khrrhgc6sVJYWqasEUPx2lssCGkUHPMeEhXHtV1k5Gpov87QU9gJG5tBQ M19pGRYAmG+2I5NYTMCWO6KxaGL31bX10KubPgz96FpgBMl/tfnU6/7M4fjvKC/O +RhK/SFtec5abOk7O3LCM5bEBywWSk8xXYDOoaYh38z8glDUydm4qwIxGFODJwBK TzkQfkgxirq7ElGjmAFgqWOWPTad0t/pUe+oQOu9YP2iAKVKS+XftpsGXImFvK/V 2l7JxzNkHRe+y7Pq1KZBUMZQNG91a2Z7P1hUjbmcFYDDR/cLCb9qpkJi+iWdVWN6 Eq9MpqXQKv3VwkAjsoSW5M7M+rZe+/jogQXaz4kWMJDgjjm2J3O86uBXfFsU1oAu Q1zEMuwe4Q4Qs22R4xvEmvsGRAx5jIz/9nwBTbmqH9s0nYN9528= =Hm3m -----END PGP SIGNATURE----- --=-=-=-- --===============0098260508== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============0098260508==--