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Mario Kleiner
fdd1fe57c0
For throttling to work correctly, we always need a baseline vblank count last_flip_vblank that increments at start of front-porch. This is the case for drm_crtc_vblank_count() in non-VRR mode, where the vblank irq fires at start of front-porch and triggers DRM core vblank handling, but it is no longer the case in VRR mode, where core vblank handling is done later, after end of front-porch. Therefore drm_crtc_vblank_count() is no longer useful for this. We also can't use drm_crtc_accurate_vblank_count(), as that would screw up vblank timestamps in VRR mode when called in front-porch. To solve this, use the cooked hardware vblank counter returned by amdgpu_get_vblank_counter_kms() instead, as that one is cooked to always increment at start of front-porch, independent of when vblank related irq's fire. This patch allows vblank irq handling to happen anywhere within vblank of even after it, without a negative impact on flip throttling, so followup patches can shift the vblank core handling trigger point wherever they need it. Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com> Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
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.