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Enric Balletbo i Serra 46f206304d drm/bridge: ps8640: Rework power state handling
The get_edid() callback can be triggered anytime by an ioctl, i.e

  drm_mode_getconnector (ioctl)
    -> drm_helper_probe_single_connector_modes
       -> drm_bridge_connector_get_modes
          -> ps8640_bridge_get_edid

Actually if the bridge pre_enable() function was not called before
get_edid(), the driver will not be able to get the EDID properly and
display will not work until a second get_edid() call is issued and if
pre_enable() is called before. The side effect of this, for example, is
that you see anything when `Frecon` starts, neither the splash screen,
until the graphical session manager starts.

To fix this we need to make sure that all we need is enabled before
reading the EDID. This means the following:

1. If get_edid() is called before having the device powered we need to
   power on the device. In such case, the driver will power off again the
   device.

2. If get_edid() is called after having the device powered, all should
   just work. We added a powered flag in order to avoid recurrent calls
   to ps8640_bridge_poweron() and unneeded delays.

3. This seems to be specific for this device, but we need to make sure
   the panel is powered on before do a power on cycle on this device.
   Otherwise the device fails to retrieve the EDID.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Bilal Wasim <bwasim.lkml@gmail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200827085911.944899-2-enric.balletbo@collabora.com
2020-09-15 15:12:24 +02:00
arch ARM: SoC fixes 2020-09-13 14:54:40 -07:00
block - Fix a regression in bdev partition locking (Christoph) 2020-09-11 11:55:28 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-08-30 15:53:44 -07:00
Documentation Merge drm/drm-next into drm-misc-next 2020-09-14 18:11:40 +02:00
drivers drm/bridge: ps8640: Rework power state handling 2020-09-15 15:12:24 +02:00
fs Driver core fixes for 5.9-rc5 2020-09-13 09:02:59 -07:00
include drm/atomic-helper: Extract drm_atomic_helper_calc_timestamping_constants() 2020-09-14 22:36:44 +03:00
init init: fix error check in clean_path() 2020-09-04 09:16:58 -07:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel Linux 5.9-rc5 2020-09-14 17:19:11 +02:00
lib Merge drm/drm-next into drm-misc-next 2020-09-14 18:11:40 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm xen: branch for v5.9-rc4 2020-09-06 09:59:27 -07:00
net NFS client bugfixes for Linux 5.9 2020-09-09 11:14:20 -07:00
samples treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
scripts Char / Misc driver fixes for 5.9-rc5 2020-09-13 08:52:21 -07:00
security treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
sound sound fixes for 5.9-rc4 2020-09-04 12:05:25 -07:00
tools KVM/arm64 fixes for Linux 5.9, take #1 2020-09-11 13:12:11 -04:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: fix memory leak in kvm_io_bus_unregister_dev() 2020-09-11 13:15:11 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2020-09-01 12:53:42 +02:00
.cocciconfig
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COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: Replace HTTP links with HTTPS ones 2020-07-23 14:53:58 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge drm/drm-next into drm-misc-next 2020-09-14 18:11:40 +02:00
Makefile Linux 5.9-rc5 2020-09-13 16:06:00 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.

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.