mirror of https://gitee.com/openkylin/linux.git
78e31c4226
On msm8998, vblank timeouts are observed because the DSI controller is not
reset properly, which ends up stalling the MDP. This is because the reset
logic is not correct per the hardware documentation.
The documentation states that after asserting reset, software should wait
some time (no indication of how long), or poll the status register until it
returns 0 before deasserting reset.
wmb() is insufficient for this purpose since it just ensures ordering, not
timing between writes. Since asserting and deasserting reset occurs on the
same register, ordering is already guaranteed by the architecture, making
the wmb extraneous.
Since we would define a timeout for polling the status register to avoid a
possible infinite loop, lets just use a static delay of 20 ms, since 16.666
ms is the time available to process one frame at 60 fps.
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.