From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamal Mostafa Subject: Re: [PATCH 2/2] drm/i915: do not setup backlight if not available according to VBT Date: Wed, 09 Apr 2014 10:01:49 -0700 Message-ID: <1397062909.9751.8.camel@fourier> References: <1397039735-2561-1-git-send-email-jani.nikula@intel.com> <1397039735-2561-2-git-send-email-jani.nikula@intel.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1907643791==" Return-path: Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by gabe.freedesktop.org (Postfix) with ESMTP id 8F7496E0AC for ; Wed, 9 Apr 2014 10:02:10 -0700 (PDT) In-Reply-To: <1397039735-2561-2-git-send-email-jani.nikula@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Jani Nikula Cc: aaron.lu@intel.com, intel-gfx@lists.freedesktop.org, kent.baxley@canonical.com, stable@vger.kernel.org, EGriffith92@gmail.com List-Id: intel-gfx@lists.freedesktop.org --===============1907643791== Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-aGb4eWBQN1Siv4gPGzEx" --=-aGb4eWBQN1Siv4gPGzEx Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2014-04-09 at 13:35 +0300, Jani Nikula wrote: > Some machines use an external EC for controlling the backlight. Info > about this is present in the VBT. Do not setup native backlight control > if no PWM backlight is available or supported according to VBT. The > acpi_backlight interface appears to work for the EC control. >=20 > In most cases there has been no harm done, but it looks like there are > machines out there that have both an EC and our PWM line connected to > the same wire. This, obviously, does not end well. >=20 > This should fix the regression caused by > commit bc0bb9fd1c7810407ab810d204bbaecb255fddde > Author: Jani Nikula > Date: Thu Nov 14 12:14:29 2013 +0200 >=20 > drm/i915: remove QUIRK_NO_PCH_PWM_ENABLE Works great! These patches do indeed re-fix backlight control in v3.14, on both of the two XPS13 models that had needed the NO_PCH_PWM_ENABLE quirk. Tested-by: Kamal Mostafa Thanks Jani! -Kamal > AFAICT the quirk removed by the above commit effectively resulted in > i915 not driving the backlight PWM output, thus not messing things up. >=20 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=3D76276 > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=3D47941 > CC: Aaron Lu > CC: Kamal Mostafa > CC: Eric Griffith > CC: Kent Baxley > CC: stable@vger.kernel.org [v3.14+] > Signed-off-by: Jani Nikula > --- > drivers/gpu/drm/i915/intel_panel.c | 5 +++++ > 1 file changed, 5 insertions(+) >=20 > diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/in= tel_panel.c > index cb058408c70e..0eead16aeda7 100644 > --- a/drivers/gpu/drm/i915/intel_panel.c > +++ b/drivers/gpu/drm/i915/intel_panel.c > @@ -1065,6 +1065,11 @@ int intel_panel_setup_backlight(struct drm_connect= or *connector) > unsigned long flags; > int ret; > =20 > + if (!dev_priv->vbt.backlight.present) { > + DRM_DEBUG_KMS("native backlight control not available per VBT\n"); > + return 0; > + } > + > /* set level and max in panel struct */ > spin_lock_irqsave(&dev_priv->backlight_lock, flags); > ret =3D dev_priv->display.setup_backlight(intel_connector); --=-aGb4eWBQN1Siv4gPGzEx 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) iQIcBAABCAAGBQJTRXz9AAoJEHqwmdxYrXhZ3a8P/A9YiasnaFm9ybN1XmZFY+kC HP+QTYzMbpzP1mKWV4r5J1QuJkY9M9mAjDrUjN/neSYQmdqbHLTx3VS9busYSc+4 dHmvMuj4jElrkREJNm68/rbqJyS7YfDmwR6bOn24Lkw/ipt9+6AxBL26EvvwlTIk qfhhfXK/9kvoQWRMwoKKHlGDXR1vdWFYQlBbQDSlaKTDH/R2xwsuB0faiCmQO9JC zMiEPvQsJPqIqbZNNspXgrdLjkhpg+o4ewKUdXbeTrbNqKHv0AOIC04Pwt7gNY/7 AMfDKbkHMpWcrOMHclQor8HoI0L3BEujXQqZL+Ht7kTg+sE/SaI7xp1LkV2KBaxx 3CVtrE4x7if3+28/E05q/1k3fN9i1QFkn1Xe5BfUjmcAo1IAnzNHysOhyIR4qxeY 8IOiRJQQqNnxxNHUCA8WuAKvcFLjGPFO9P7Y6mqX1lTA6xg1P1ZrR1OhSsH0OQdW Ulr7kqeswCZ4RL04xSpyVnwQ98x/PUU9v+swNJHeY9moJe+6ghOzSV7wiylZfZwt EUci9nLkOfD5kl++q8Pdqskgs0RvTTZ3d12Jg+7CuG/LpACuF8vz5hJeP0aievMj +010joImf7dDqCHoM0NZuM4l/fGZvjZrkPUMeSd0F2+xt6A41Cg6wIfwQxTLF4uA sZ/9/EAdU+GCl4d3W4H6 =e4lB -----END PGP SIGNATURE----- --=-aGb4eWBQN1Siv4gPGzEx-- --===============1907643791== 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 --===============1907643791==--