From mboxrd@z Thu Jan 1 00:00:00 1970 From: Imre Deak Subject: Re: [PATCH 12/14] drm/i915: Turn on panel power before doing aux transfers Date: Tue, 02 Sep 2014 17:02:38 +0300 Message-ID: <1409666558.15662.17.camel@intelbox> References: <1408389369-22898-1-git-send-email-ville.syrjala@linux.intel.com> <1408389369-22898-13-git-send-email-ville.syrjala@linux.intel.com> Reply-To: imre.deak@intel.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1920838120==" Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTP id 66F0689364 for ; Tue, 2 Sep 2014 07:02:41 -0700 (PDT) In-Reply-To: <1408389369-22898-13-git-send-email-ville.syrjala@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: ville.syrjala@linux.intel.com Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org --===============1920838120== Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-Odr2/EO1LcXF55tVjevc" --=-Odr2/EO1LcXF55tVjevc Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2014-08-18 at 22:16 +0300, ville.syrjala@linux.intel.com wrote: > From: Ville Syrj=C3=A4l=C3=A4 >=20 > On VLV/CHV the panel power sequencer may need to be "kicked" a bit to > lock onto the new port, and that needs to happen before any aux > transfers are attempted if we want the aux transfers to actaully > succeed. So turn on panel power (part of the "kick") before aux > transfers (DPMS_ON + link training). >=20 > This also matches the documented modeset sequence better for pch > platforms. The documentation doesn't explicitly state anything about the > DPMS or link training DPCD writes, but the panel power on step is > always listed before link training is mentioned. >=20 > Signed-off-by: Ville Syrj=C3=A4l=C3=A4 Jani had the same change in: https://bugs.freedesktop.org/show_bug.cgi?id=3D70117 which solved link training issues, so we could add a reference to that bug and ask the reporters to retest. The patch looks ok: Reviewed-by: Imre Deak > --- > drivers/gpu/drm/i915/intel_dp.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) >=20 > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel= _dp.c > index 4952783..28bc652 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -2275,10 +2275,10 @@ static void intel_enable_dp(struct intel_encoder = *encoder) > return; > =20 > intel_edp_panel_vdd_on(intel_dp); > - intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > - intel_dp_start_link_train(intel_dp); > intel_edp_panel_on(intel_dp); > intel_edp_panel_vdd_off(intel_dp, true); > + intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > + intel_dp_start_link_train(intel_dp); > intel_dp_complete_link_train(intel_dp); > intel_dp_stop_link_train(intel_dp); > } --=-Odr2/EO1LcXF55tVjevc 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 v1.4.14 (GNU/Linux) iQEcBAABAgAGBQJUBc3+AAoJEORIIAnNuWDFZy4H/2s4pQK7RCLIRWPW1KWLQX6c ZCjYYX2qfFYRq2BYx8N0Vgk6bC3/0NBoqTCRvu6WrEC3QEd5HoX1OqbVfArW8C+X L0OM0IaB5V7sJSREsbgkYwdRvh05kIsoui11Aql/+HVBWihQ5hKhCUXV6lre818E qcCeiQNiKxM052+N8WKkpLS4fETBuSEihZY79PBN52uE4e91eiO+Sy17QXU0c4ms 5nW/AxKKBrcBelNFdrxhYjH4TgmqkETu+53eDoD1937UqM2N8xZcMTtr3nNrjJ4u K02FwnAHcpSF3yan4NmYfrk7Y/LnBhiOfQU45xCaYTZfgmFaoXpaQ7yZBR9tj80= =QtXU -----END PGP SIGNATURE----- --=-Odr2/EO1LcXF55tVjevc-- --===============1920838120== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx --===============1920838120==--