'\" t .\" Title: drm_get_last_vbltimestamp .\" Author: .\" Generator: DocBook XSL Stylesheets v1.78.1 .\" Date: May 2018 .\" Manual: DRM Core .\" Source: Kernel Hackers Manual 3.16.56 .\" Language: English .\" .TH "DRM_GET_LAST_VBLTIME" "9" "May 2018" "Kernel Hackers Manual 3\&.16\&" "DRM Core" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" drm_get_last_vbltimestamp \- retrieve raw timestamp for the most recent vblank interval .SH "SYNOPSIS" .HP \w'u32\ drm_get_last_vbltimestamp('u .BI "u32 drm_get_last_vbltimestamp(struct\ drm_device\ *\ " "dev" ", int\ " "crtc" ", struct\ timeval\ *\ " "tvblank" ", unsigned\ " "flags" ");" .SH "ARGUMENTS" .PP \fIdev\fR .RS 4 DRM device .RE .PP \fIcrtc\fR .RS 4 which CRTC\*(Aqs vblank timestamp to retrieve .RE .PP \fItvblank\fR .RS 4 Pointer to target struct timeval which should receive the timestamp .RE .PP \fIflags\fR .RS 4 Flags to pass to driver: 0 = Default, DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler .RE .SH "DESCRIPTION" .PP 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\&. .PP Returns zero if timestamp originates from uncorrected \fBdo_gettimeofday\fR call, i\&.e\&., it isn\*(Aqt very precisely locked to the true vblank\&. .SH "RETURNS" .PP Non\-zero if timestamp is considered to be very precise, zero otherwise\&. .SH "AUTHORS" .PP \fBJesse Barnes\fR <\&jesse.barnes@intel.com\&> .br Intel Corporation, .RS 4 Initial version .RE .PP \fBLaurent Pinchart\fR <\&laurent.pinchart@ideasonboard.com\&> .br Ideas on board SPRL, .RS 4 Driver internals .RE .PP \fBDaniel Vetter\fR <\&daniel.vetter@ffwll.ch\&> .br Intel Corporation, .RS 4 Contributions all over the place .RE .SH "COPYRIGHT" .br