From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesse Barnes Subject: Re: [Intel-gfx] [PATCH 5/7] drm/i915: Make DP prepare/commit consistent with DP dpms Date: Thu, 3 Nov 2011 15:41:25 -0700 Message-ID: <20111103154125.1fdaff5c@jbarnes-desktop> References: <1320214830-12696-1-git-send-email-keithp@keithp.com> <1320214830-12696-6-git-send-email-keithp@keithp.com> <20111103130011.7946090a@jbarnes-desktop> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/TTwxyYHj.52/ahrGaEtupnd"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Keith Packard Cc: intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org --Sig_/TTwxyYHj.52/ahrGaEtupnd Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 03 Nov 2011 15:30:57 -0700 Keith Packard wrote: > On Thu, 3 Nov 2011 13:00:11 -0700, Jesse Barnes wrote: >=20 > > A few comments on this one (also, is it strictly required to fix your > > bug)? >=20 > I think so; the panel definitely was not happy when I turned the link > off while the panel power was on. Having the mode setting and DPMS paths > doing things in different orders definitely doesn't seem reasonable > though. I nearly managed to share code between the two paths, but there > are subtle differences in requirements and so I didn't bother. >=20 > > Ok so you're making sure the panel has power to down the link, I think > > that's fine. >=20 > No, I'm turning the panel off *before* turning off the link. The panel > goes nuts if you down the link before turning its power off; lots of > technicolor. Except for VDD?? That does come on... and shouldn't be any different than a full power sequence as far as link training etc go... > Downing the link doesn't require any communication with the panel, so > there's no issue with losing connectivity at this point: >=20 > ironlake_edp_backlight_off(intel_dp); > ironlake_edp_panel_off(intel_dp); <=3D panel off >=20 > /* Wake up the sink first */ > ironlake_edp_panel_vdd_on(intel_dp); > intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > intel_dp_link_down(intel_dp); <=3D link down > ironlake_edp_panel_vdd_off(intel_dp, false); >=20 > > But here it looks like you're shutting it off, then downing the link? > > Should this be reordered? >=20 > Nope, it's in the same order: >=20 > ironlake_edp_backlight_off(intel_dp); > ironlake_edp_panel_off(intel_dp); <=3D panel off >=20 > ironlake_edp_panel_vdd_on(intel_dp); > intel_dp_sink_dpms(intel_dp, mode); > intel_dp_link_down(intel_dp); <=3D link down > ironlake_edp_panel_vdd_off(intel_dp, false); >=20 > The only difference in these two code paths is that dp_prepare turns the > sink to DPMS_ON, while dp_dpms turns the sink to DPMS_OFF. Oh missed the vdd on, which is in this path too... So I'm still confused by the panel off, vdd on sequence, but at least they're consistent. --=20 Jesse Barnes, Intel Open Source Technology Center --Sig_/TTwxyYHj.52/ahrGaEtupnd Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQIcBAEBAgAGBQJOsxiVAAoJEIEoDkX4Qk9h3V0P/3RKsY6aNwPWCOyNmxlzB5pR N9tgdMSCPslq6Acnt3sAaRnVdZDuTQcN4yGnTFNL60xgyad2j5Cv5CB3KRvMfVEs KITgELtQaOjulp7EEWJWf0Z0VS1mH3X8qtYMERn54UHV49JOrgQNpot82RYjQBlw wWuOw263xGu+JY3OuVW+4NvUxWSQN5iUlDQqzBBJoLWc2CheKfuIjtm1uBL3oZdg VsVzkrvPAvt80CSQYs4ZIzkWlh+iZ4SYFL60aEfmMTfjsbwOjmjdmUDfkFRVwkE1 TV+dT17A4T8H+lWKNS4JAETfM+FmMoSajM/HXrdpSbrW7A+Iy9DbvZNiap7BkA7C HcYNJs02PO0h2V2Fj8yYNpTrkswHEg0QL5Y+UyoUzAH02gB8Mb2icWU5yDzJ75wb GljYk3kSRcFYuGHNAzk06FdeFoqnHoy2mLLhNuzwsqfhJARp2Ci7eI5UeuDush1z emWMnSWZMxeYiPxuzvXrCOWnlaKhqyW/nUwbYns6PjTZNXZgqHEZ9zzdNSvTTON3 yeL4w1iBRQWB/7Oa0tfKY1/+I01G3pt1EbwyIhfU9LvO843py58L9EI0rZ0w5gK5 T847yyx7QqpTB74lpaWODlbqM+pbgFFOn+O/UjP7ds1IhbG1VfVBGS3ilbURrtcO nOhdaABqSg1HKMrJ82we =qdxc -----END PGP SIGNATURE----- --Sig_/TTwxyYHj.52/ahrGaEtupnd--