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Filename Latest commit message Latest commit date
Hersen Wu f8ac2cf78f drm/amd/display: Linux set/read lane settings through debugfs
function: get current DP PHY settings: voltage swing, pre-emphasis,
 post-cursor2 (defined by VESA DP specification)

 valid values:  voltage swing: 0,1,2,3  pre-emphasis : 0,1,2,3
 post cursor2 : 0,1,2,3

 debugfs file phy_setings is located at  /sys/kernel/debug/dri/0/DP-x

 there will be directories, like DP-1, DP-2,DP-3, etc. for DP display

 --- to figure out which DP-x is the display for DP to be check,
 cd DP-x
 ls -ll
 There should be debugfs file, like link_settings, phy_settings.
 cat link_settings
 from lane_count, link_rate to figure which DP-x is for display to be
 worked on

 --- to get current DP PHY settings,
 cat phy_settings

 --- to change DP PHY settings,
 echo <voltage_swing> <pre-emphasis> <post_cursor2> > phy_settings

 for examle, to change voltage swing to 2, pre-emphasis to 3,
 post_cursor2 to 0,
 echo 2 3 0 > phy_settings

 ---  to check if change be applied, get current phy settings by
 cat phy_settings

 ---  in case invalid values are set by user, like
 echo 1 4 0 > phy_settings

 HW will NOT be programmed by these settings.

cat phy_settings will show the previous valid settings.

Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2018-07-13 14:49:36 -05:00
arch Merge branch 'parisc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2018-06-30 14:16:30 -07:00
block for-linus-20180629 2018-06-30 10:47:46 -07:00
certs certs/blacklist: fix const confusion 2018-06-26 09:43:03 -07:00
crypto Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
Documentation Merge branch 'drm-next-4.19' of git://people.freedesktop.org/~agd5f/linux into drm-next 2018-07-10 10:57:08 +10:00
drivers drm/amd/display: Linux set/read lane settings through debugfs 2018-07-13 14:49:36 -05:00
firmware
fs for-4.18-rc2-tag 2018-07-01 12:38:16 -07:00
include drm/scheduler: modify args of drm_sched_entity_init 2018-07-13 14:46:05 -05:00
init Kbuild fixes for v4.18 2018-06-30 13:05:30 -07:00
ipc
kernel drm-misc-next for 4.19: 2018-07-06 10:01:56 +10:00
lib Merge branch 'vmwgfx-next' of git://people.freedesktop.org/~thomash/linux into drm-next 2018-07-06 08:47:14 +10:00
LICENSES
mm slub: fix failure when we delete and create a slab cache 2018-06-28 11:16:44 -07:00
net net: handle NULL ->poll gracefully 2018-06-29 06:51:51 -07:00
samples
scripts Kbuild fixes for v4.18 2018-06-30 13:05:30 -07:00
security selinux/stable-4.18 PR 20180629 2018-06-30 11:15:12 -07:00
sound ALSA: seq: Fix UBSAN warning at SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT ioctl 2018-06-25 11:18:04 +02:00
tools Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-30 11:42:14 -07:00
usr
virt KVM: arm64: Prevent KVM_COMPAT from being selected 2018-06-21 17:17:50 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS proc: add Alexey to MAINTAINERS 2018-06-28 11:16:44 -07:00
Makefile Linux 4.18-rc3 2018-07-01 16:04:53 -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.