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 <[email protected]>
Intel Corporation,         
        

Initial version

Laurent Pinchart <[email protected]>
Ideas on board SPRL,         
        

Driver internals

Daniel Vetter <[email protected]>
Intel Corporation,         
        

Contributions all over the place

COPYRIGHT