No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Jani Nikula 6209c285e7 drm/i915: set DP Main Stream Attribute for color range on DDI platforms
Since Haswell we have no color range indication either in the pipe or
port registers for DP. Instead, there's a separate register for setting
the DP Main Stream Attributes (MSA) directly. The MSA register
definition makes no references to colorimetry, just a vague reference to
the DP spec. The connection to the color range was lost.

Apparently we've failed to set the proper MSA bit for limited, or CEA,
range ever since the first DDI platforms. We've started setting other
MSA parameters since commit dae847991a ("drm/i915: add
intel_ddi_set_pipe_settings").

Without the crucial bit of information, the DP sink has no way of
knowing the source is actually transmitting limited range RGB, leading
to "washed out" colors. With the colorimetry information, compliant
sinks should be able to handle the limited range properly. Native
(i.e. non-LSPCON) HDMI was not affected because we do pass the color
range via AVI infoframes.

Though not the root cause, the problem was made worse for DDI platforms
with commit 55bc60db59 ("drm/i915: Add "Automatic" mode for the
"Broadcast RGB" property"), which selects limited range RGB
automatically based on the mode, as per the DP, HDMI and CEA specs.

After all these years, the fix boils down to flipping one bit.

[Per testing reports, this fixes DP sinks, but not the LSPCON. My
 educated guess is that the LSPCON fails to turn the CEA range MSA into
 AVI infoframes for HDMI.]

Reported-by: Michał Kopeć <mkopec12@gmail.com>
Reported-by: N. W. <nw9165-3201@yahoo.com>
Reported-by: Nicholas Stommel <nicholas.stommel@gmail.com>
Reported-by: Tom Yan <tom.ty89@gmail.com>
Tested-by: Nicholas Stommel <nicholas.stommel@gmail.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=100023
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107476
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=94921
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.9+
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180814060001.18224-1-jani.nikula@intel.com
(cherry picked from commit dc5977da99)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2018-08-15 13:41:10 -07:00
arch BackMerge v4.18-rc7 into drm-next 2018-07-30 10:39:22 +10:00
block for-linus-20180727 2018-07-27 12:51:00 -07:00
certs
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-07-19 07:32:44 -07:00
Documentation Merge tag 'drm-msm-next-2018-07-30' of git://people.freedesktop.org/~robclark/linux into drm-next 2018-08-01 08:52:19 +10:00
drivers drm/i915: set DP Main Stream Attribute for color range on DDI platforms 2018-08-15 13:41:10 -07:00
firmware
fs Some miscellaneous ext4 fixes for 4.18; one fix is for a regression 2018-07-29 13:13:45 -07:00
include Merge branch 'drm-next-4.19' of git://people.freedesktop.org/~agd5f/linux into drm-next 2018-08-08 06:22:23 +10:00
init
ipc ipc/sem.c: prevent queue.status tearing in semop 2018-07-26 19:38:03 -07:00
kernel BackMerge v4.18-rc7 into drm-next 2018-07-30 10:39:22 +10:00
lib BackMerge v4.18-rc7 into drm-next 2018-07-30 10:39:22 +10:00
LICENSES
mm zswap: re-check zswap_is_full() after do zswap_shrink() 2018-07-26 19:38:03 -07:00
net ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull 2018-07-24 16:35:58 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-18 19:32:54 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-18 19:32:54 -07:00
security
sound ALSA: hda/realtek - Yet another Clevo P950 quirk entry 2018-07-18 12:17:46 +02:00
tools Various fixes to the tracing infrastructure: 2018-07-27 09:50:33 -07:00
usr
virt Miscellaneous bugfixes, plus a small patchlet related to Spectre v2. 2018-07-18 11:08:44 -07:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS BackMerge v4.18-rc7 into drm-next 2018-07-30 10:39:22 +10:00
Makefile Linux 4.18-rc7 2018-07-29 14:44:52 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.