f59769c52c
When initially turning a crtc on, drm_reset_vblank_timestamp will set the vblank timestamp to 0 for any driver that doesn't provide a ->get_vblank_timestamp() hook. Unfortunately, the FLIP_COMPLETE event depends on that timestamp, and the only way to regenerate a valid one is to have vblank interrupts enabled and have a valid in-ISR call to drm_crtc_handle_vblank. Additionally, if the user doesn't request vblanks but _does_ request FLIP_COMPLETE events, we still don't have a good timestamp: it'll be the same stamp as the last vblank one. Work around the issue by always enabling vblanks when the CRTC is on. Reducing the amount of time that PL0 has to be unmasked would be nice to fix at a later time. Changes since v1 [https://patchwork.freedesktop.org/patch/331727/]: - moved drm_crtc_vblank_put call to the ->atomic_disable() hook Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com> Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com> Signed-off-by: Ayan kumar halder <ayan.halder@arm.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191001142121.13939-1-mihail.atanassov@arm.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.