From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Subject: Re: [PATCH 0/2] OMAPDSS: DISPC: Improvements to DIGIT sync signal selection Date: Mon, 30 Jul 2012 14:11:56 +0300 Message-ID: <1343646716.8019.22.camel@lappyti> References: <1343434897-8444-1-git-send-email-ricardo.neri@ti.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-do0HIPNpbkzFbR3fmUcq" Return-path: Received: from na3sys009aog135.obsmtp.com ([74.125.149.84]:39276 "EHLO na3sys009aog135.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753232Ab2G3LMA (ORCPT ); Mon, 30 Jul 2012 07:12:00 -0400 Received: by lbgc1 with SMTP id c1so2924785lbg.15 for ; Mon, 30 Jul 2012 04:11:57 -0700 (PDT) In-Reply-To: <1343434897-8444-1-git-send-email-ricardo.neri@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Ricardo Neri Cc: archit@ti.com, s-guiriec@ti.com, linux-omap@vger.kernel.org --=-do0HIPNpbkzFbR3fmUcq Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2012-07-27 at 19:21 -0500, Ricardo Neri wrote: > Hello, >=20 > DSS code wrongly assumes that VENC is always available as source for the = external > sync signal for the display controller DIGIT channel. One cannot blindly > rely only on the value of DSS_CONTROL register as certain processors may = not > have VENC (e.g., OMAP5). >=20 > These patches add logic to correctly set/get the sync signal based on the > available displays in the DIGIT channel. >=20 > For the HDMI driver, handle the error in the selection of the source. Is there an actual problem seen that this resolves? If so, It'd be nice to have a brief description of the problem. Does the bit 15 in DSS_CONTROL still exist on OMAP5? What does it return on OMAP5? I think it's clear that dss_get_hdmi_venc_clk_source() needs to return a correct value so that DSS operates correctly. But I'm not sure we need the extra code in dss_select_hdmi_venc_clk_source(). dss_select_hdmi_venc_clk_source() should be called by venc or hdmi, and there should be any possibility of using it in the wrong way. For extra sanity checking there could be a BUG_ON() check in the dss_select_hdmi_venc_clk_source() to point out if there's a bad bug in venc or hdmi. I'd like to keep the lowest level dss-internal functions as simple as possible, and written in the manner that they presume they are called correctly. Otherwise we'll end up with lots of new code, checking for errors that can never happen in practice. Tomi --=-do0HIPNpbkzFbR3fmUcq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAABAgAGBQJQFmv8AAoJEPo9qoy8lh718rcQAK3Qw73OYbOl1F30GaFEJHKP ZhiysGOFLfmU5OjKmiGm1GVJYQlD6zuy43q2sHxGuQv9CsLy3nBIAd7yqQIYM5MB 5XK3Cko37QtpCd+FdtDhrY1sexU1GmaJLr62IkFndgxvt1MSjjKnlW01A/4NBKk1 cP1usICbO19B77CWqkEhq4C+as2RqepDyFR8MbbS8JdnLkoAC95ypuugIrpy8U2r BGxC0H0vO5vST39NAzmJbg0V/QwKUV6qZDqJLsVDzteabl4EtN3haeLsnhzzGzLi Jl72fbDUi2jHvWp25Lsqha8zLrManSifZUaJOq4S8oS1UWEQj+k+TEhROesUS/sW NZXguFnnPvCbJZc++6oICTjI+sUJSBC/Hr5rFerKp6Qtyzx2Pe0fYaTVsMoL9+9e 38IaXOSHC0dEpLM6ePVLdQpD1bG23OaZglXmeFrXA7Qg92Ve2Njg/ph5eaDj3bWW JSxpWzcPJHEGWNCcAm6OQu01m443de9IxxeyVtlffKAKGn1j6NYPkd+yfOMDTDmc 9SGtKDedPLxqtNzEEgqW1gqprBiZ7UpwXprmF66Z9f/1p8XO1Mlww2hO23/GGck/ 0Rle1fNmcZRF/3b47h1rM64ig6WGPQ/flzNVNjqEVeUg3ddFlPfl/EYELS8KJKLw Xsb9zbQ9n28ujmg87pdf =5d42 -----END PGP SIGNATURE----- --=-do0HIPNpbkzFbR3fmUcq--