From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: DSS2/PM on 3.2 broken? Date: Wed, 18 Jan 2012 22:15:38 +1100 Message-ID: <20120118221538.342b4782@notabene.brown> References: <20120110080849.5a242adf@notabene.brown> <20120112095940.0a54413e@notabene.brown> <20120113222045.37f9b4ec@notabene.brown> <1326870839.1954.23.camel@deskari> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/WB9RGT+G6qp=E79hO35ITpr"; protocol="application/pgp-signature" Return-path: Received: from cantor2.suse.de ([195.135.220.15]:52303 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750715Ab2ARLPx (ORCPT ); Wed, 18 Jan 2012 06:15:53 -0500 In-Reply-To: <1326870839.1954.23.camel@deskari> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tomi Valkeinen Cc: Paul Walmsley , Joe Woodward , khilman@ti.com, t-kristo@ti.com, govindraj.r@ti.com, linux-omap@vger.kernel.org --Sig_/WB9RGT+G6qp=E79hO35ITpr Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Wed, 18 Jan 2012 09:13:59 +0200 Tomi Valkeinen wrote: > On Fri, 2012-01-13 at 22:20 +1100, NeilBrown wrote: > > Having CPUIDLE makes the DSS2 problem worse: lots of=20 > >=20 > > [ 21.085113] omapdss DISPC error: SYNC_LOST on channel lcd, > > restarting the output with video overlays disabled > >=20 > > messages whenever the CPU isn't busy. >=20 > I'm not sure if it is the case here, but DSS has restrictions about the > max DSS clocks on different OPPs. For example, on OMAP4430 LCD clock > maximum is 186MHz at OPP100, and 93MHz at OPP50. So it's a quite big > drop, causing problems with all but the rather small displays. >=20 > And the DSS driver doesn't have any support to handle this at the > moment, as there isn't support in the PM framework to do this. I think > the only way to handle this at the moment is for the DSS driver to set > an arbitrarily high constraint on, say, mem throughput, and hope that it > keeps the OMAP in the required OPP. >=20 > Tomi >=20 This LCD panel on this device sets: .pixel_clock =3D 22000, in the "struct omap_video_timings" so I'm guessing that is 22MHz? I'll try building without SMARTREFLEX and see if that makes a difference - presumably that should keep it at OPP100 (??). Thanks, NeilBrown --Sig_/WB9RGT+G6qp=E79hO35ITpr Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBTxap2jnsnt1WYoG5AQJVWg/9FYN0QEQvRtdD5ap5cqKfwqdnXZPwD/KM bieSlIaCYPOqnytPvJGGINWwvPHial0kS0c3CvwuF/n2oaMujnbZb5DiTnALcG4b IQaltRkk1HB+OM6D9sIF77OlFbONzvtoYGpivyy6ycNn5e3rriUUB5v7ez5SrZsp mviHHScdVb8WsQOX/eg2dqqMLcpq6FE1yktlgZ+ILVQmtlAP9MlnEluXO6S4Ma7A 62cty8vpIQWC4Vex1HzXWjj29YbQNnVPricgpstl6ovnZlr0mX+sq0u3gz16ShB+ B83MYKOL4tRHfytUXP6zNW3Q4oytbRIa2oUYE2azBha8qQFCTfPufpa67JCRqU2k y/5oK2K+qmMd7HVWZdXdKaCPdxGr7ZXgN0UE9hmIOh4rHp5tIwGv6QmnZJ8gF2sJ j4NgxkoroS28iUx2sw6ImjdbWVPr0huWzFbRT6xuRBP75IN0+Y29G6uhiaAG+1xL xyOWaDTbz+v+rvkBzI9whGBHTU1mUJARrTpHJkf/B7pcqbTENK7DG62RNqjq2mIk SPNa+WkkwQd6YPFSN26pd//FzbWg+JeqEtVnrtQt32scQvgbcMmpiA/SZyHJ1rBd D8JflrWllLIHwS8KriX+YU11JTIgK1HPuqQtBfWp89nlJ7hEOW6hSDPjoKXMebSd OgIJQ/dAcsA= =2+is -----END PGP SIGNATURE----- --Sig_/WB9RGT+G6qp=E79hO35ITpr--