Scroll to navigation

DRM_GET_LAST_VBLTIME(9) DRM Core DRM_GET_LAST_VBLTIME(9)

NAME

drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent vblank interval

SYNOPSIS

u32 drm_get_last_vbltimestamp(struct drm_device * dev, int crtc, struct timeval * tvblank, unsigned flags);

ARGUMENTS

dev
DRM device
crtc
which CRTC's vblank timestamp to retrieve
tvblank
Pointer to target struct timeval which should receive the timestamp
flags
Flags to pass to driver: 0 = Default, DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler

DESCRIPTION

Fetches the system timestamp corresponding to the time of the most recent vblank interval on specified CRTC. May call into kms-driver to compute the timestamp with a high-precision GPU specific method.
Returns zero if timestamp originates from uncorrected do_gettimeofday call, i.e., it isn't very precisely locked to the true vblank.

RETURNS

Non-zero if timestamp is considered to be very precise, zero otherwise.

AUTHORS

Jesse Barnes <jesse.barnes@intel.com>
 
Intel Corporation,
Initial version
Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 
Ideas on board SPRL,
Driver internals
Daniel Vetter <daniel.vetter@ffwll.ch>
 
Intel Corporation,
Contributions all over the place

COPYRIGHT

May 2018 Kernel Hackers Manual 3.16