mirror of https://github.com/torvalds/linux.git
375a126090
Two stages are required to setup up main link to be ready to transmit
video stream.
Stage 1: dp_hpd_plug_handle() perform link training to set up main link
stage 2: user space framework (msm_dp_display_enable()) to enable pixel
clock and transfer main link to video ready state.
At current implementation, when dongle unplugged dp_hdp_unplug_handle()
has to wait until stage 2 completed before it can send link down uevent
to user space framework to disable pixel clock followed by tearing down
main link. This introduce unnecessary latency if dongle unplugged happen
after stage 1 and before stage 2. It also has possibility leave main link
stay at ready state after dongle unplugged if framework does not response
to link down uevent notification. This will prevent next dongle plug in
from working. This scenario could possibly happen when dongle unplug while
system in the middle of suspending.
This patch allow unplug handle to tear down main link and notify
framework link down immediately if dongle unplugged happen after
stage 1 and before stage 2. With this approach, dp driver is much
more resilient to any different scenarios. Also redundant both
dp_connect_pending_timeout() and dp_disconnect_pending_timeout()
are removed to reduce logic complexity.
Changes in V2:
-- return -EINVAL at msm_dp_display_enable() if not in correct state
-- replace ST_CONNECT_PENDING with ST_MAINLINK_READY
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.
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.