ba420afab5
When the vblank irq happens, kernel time subsystem executes `vkms_vblank_simulate`. In parallel or not, it prepares all stuff necessary to the next vblank with arm, and it must flush these stuff before the next vblank irq. However, vblank counter is ahead when arm is executed in parallel with handle vblank. CPU 0: CPU 1: | | atomic_commit_tail is ongoing | | | | hrtimer: vkms_vblank_simulate() | | | drm_crtc_handle_vblank() | | drm_crtc_arm_vblank() | | | ->get_vblank_timestamp() | | | | hrtimer_forward_now() Then, we should guarantee that the vblank interval time is correct (not changed) before finish the vblank handle. Fix the bug including the call to `hrtimer_forward_now()` in the same lock of `drm_crtc_handle_vblank()` to ensure that the timestamp update is correct when finish the vblank handle. Signed-off-by: Shayenne Moura <shayenneluzmoura@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/e2e4b8f3a5cab7b2dba75bf1930f86b0a4ee08c9.1548856186.git.shayenneluzmoura@gmail.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.