From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jyri Sarha Subject: Re: [PATCH v2 2/3] drm/omapdrm: Work-a-round for errata i734 (LCD1 Gamma) in DSS dispc Date: Tue, 24 May 2016 00:02:23 +0300 Message-ID: <57436FDF.8000406@ti.com> References: <6c6551b5f9543c954467448d3c4f71b74eca7c84.1464010715.git.jsarha@ti.com> <57431C69.60709@ti.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0436612784==" Return-path: Received: from devils.ext.ti.com (devils.ext.ti.com [198.47.26.153]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2B6CB6E5B0 for ; Mon, 23 May 2016 21:02:37 +0000 (UTC) In-Reply-To: <57431C69.60709@ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Tomi Valkeinen , dri-devel@lists.freedesktop.org Cc: peter.ujfalusi@ti.com, laurent.pinchart@ideasonboard.com List-Id: dri-devel@lists.freedesktop.org --===============0436612784== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="EPPX499DdTmeWKFRRIajVlAAh5Med9Ac2" --EPPX499DdTmeWKFRRIajVlAAh5Med9Ac2 Content-Type: multipart/mixed; boundary="iFDRIO7XooDmRMMg5gH7n1i58IK2u98DA" From: Jyri Sarha To: Tomi Valkeinen , dri-devel@lists.freedesktop.org Cc: airlied@linux.ie, daniel@ffwll.ch, peter.ujfalusi@ti.com, bparrot@ti.com, laurent.pinchart@ideasonboard.com Message-ID: <57436FDF.8000406@ti.com> Subject: Re: [PATCH v2 2/3] drm/omapdrm: Work-a-round for errata i734 (LCD1 Gamma) in DSS dispc References: <6c6551b5f9543c954467448d3c4f71b74eca7c84.1464010715.git.jsarha@ti.com> <57431C69.60709@ti.com> In-Reply-To: <57431C69.60709@ti.com> --iFDRIO7XooDmRMMg5gH7n1i58IK2u98DA Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 05/23/16 18:06, Tomi Valkeinen wrote: >> For gamma tables to work on LCD1 the GFX plane has to be used at least= >> > once after DSS HW has come out of reset. The work-a-round sets up a >> > minimal LCD setup with GFX plane and waits for one vertical sync irq= >> > before disabling the setup and continuing with the context >> > restore. The physical outputs are gated during the operation. This >> > work-a-round requires that gamma table's LOADMODE is set to 0x2 in >> > DISPC_CONTROL1 register. > This LOADMODE comment is a bit odd. You should say why, and how it's > handled, and what's "0x2". But then, I'm not sure if the whole comment > is needed at all. The driver is made to work only with LOADMODE=3D2. >=20 It is there also in the comment and my point is to notify that if the gamma support is ever changed to use some other mode, the workaround needs to change too. It is pretty hard to draw the line to how deep in details one should go in comments or commit descriptions. I added the register name so that someone is interested he can find the full description of the LOADMODE from TRM using that as a key word. I think I wont mention the LOADMODE in the description but leave it on the code comments. > Maybe the real point here is that the WA needs to happen after the > initial DSS register config. >=20 I think that detail should be in the code comments, if it is needed at al= l. BR, Jyri --iFDRIO7XooDmRMMg5gH7n1i58IK2u98DA-- --EPPX499DdTmeWKFRRIajVlAAh5Med9Ac2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJXQ2/kAAoJEJA2s1DX1hlB1KcP/3hDe8V/dXLwLy2OrNzgqh5y envzW26FtuFrk2/PvEJR/WwDsnihTFxpDMISVPFZkaY4eBLCGdGU8KEnCf0uVOzD bf2jTyLr2xRDjjKSfuUNI1ovirqlQvUi+/gqveZ1ebQ6HxH8wbjIbxIe7RZ2A5HL k3G3gCFfCmiNICW8FYPfvV6g6H911MnXQXyPPxukA3myQaxSY7YFdhNDmOja00qF 5YNpm3MsBVZi8bMyByb9RZklWuhRC0xD/gr8s99JKIaXGXyzeoj4WqncZKzX3HPe sMrq/4UwBuzGHEPIQK9UPWynysncwfqNoYNQ2Gm+D+xQP4wd+xCf37qOwRaodzZi bPpAXlmaepHA7gFJZA6pTcQHcguu1tz6E83pyvmua57r2f/GnXIGQs240au57Bho 2M6Cxs3Pag/ee9vOJIREhByv6BCA63UcBD2qbagZmuay7JVRGe2lGsglD3V3sfSC Iuq1CaDJlKjVKCDoyjEDqVQrIOUIzyulcn3ZYpdVirwSMBPP2Zz4sMQ8OU2c5hfp zbWGUbYs209L+HDSdzQeRbTxM5HjYSBUH1tGrN7e5CIXptpXG9nvyCJhNmZXv77h GlRpheq7fQZborBtqJOXrOzC4L8ggGmVzuGY1UaVnX9Z9zGc+zfRmRmHNRpKdzJR sPK+TPwkrsXfT88kxyLS =c5f1 -----END PGP SIGNATURE----- --EPPX499DdTmeWKFRRIajVlAAh5Med9Ac2-- --===============0436612784== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============0436612784==--