829270e455
Since we try and estimate how long we require to update the registers to
perform a plane update, it is of vital importance that we measure the
distribution of plane updates to better guide our estimate. If we
underestimate how long it takes to perform the plane update, we may
slip into the next scanout frame causing a tear. If we overestimate, we
may unnecessarily delay the update to the next frame, causing visible
jitter.
Replace the warning that we exceed some arbitrary threshold for the
vblank update with a histogram for debugfs.
v2: Add a per-crtc debugfs entry so that the information is easier to
extract when testing individual CRTC, and so that it can be reset before
a test.
v3: Flip the graph on its side; creates space to label the time axis.
Updates: 4684
|
1us |
|
4us |********
|**********
16us |***********
|*****
66us |
|
262us |
|
1ms |
|
4ms |
|
17ms |
|
Min update: 5918ns
Max update: 54781ns
Average update: 16628ns
Overruns > 250us: 0
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1982
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> #v2
Link: https://patchwork.freedesktop.org/patch/msgid/20201202212814.26320-1-chris@chris-wilson.co.uk
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|---|---|---|
| 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.