318 	 * to complete in this vblank? GET_DISTANCE_TO_VBLANKSTART provides  in radeon_crtc_handle_vblank()
319 	 * distance to start of "fudged earlier" vblank in vpos, distance to  in radeon_crtc_handle_vblank()
320 	 * start of real vblank in hpos. vpos >= 0 && hpos < 0 means we are in  in radeon_crtc_handle_vblank()
321 	 * the last few scanlines before start of real vblank, where the vblank  in radeon_crtc_handle_vblank()
324 	 * vblank. On pre-AVIVO hardware, flips also complete inside the real  in radeon_crtc_handle_vblank()
325 	 * vblank, not only at leading edge, so if update_pending for hpos >= 0  in radeon_crtc_handle_vblank()
326 	 *  == inside real vblank, the flip will complete almost immediately.  in radeon_crtc_handle_vblank()
331 	 * vblank, leading to a delayed emission of the flip completion event.  in radeon_crtc_handle_vblank()
333 	 * completing inside vblank, not only at leading edge of vblank.  in radeon_crtc_handle_vblank()
342 		/* crtc didn't flip in this target vblank interval,  in radeon_crtc_handle_vblank()
450 	 * flip completion handling from vblank irq, as these old asics don't  in radeon_flip_work_func()
1779  *              USE_REAL_VBLANKSTART to use the real start of vblank instead
1780  *              of a fudged earlier start of vblank.
1783  *              fudged earlier start of vblank in *vpos and the distance
1784  *              to true start of vblank in *hpos.
1794  * Returns vpos as a negative number inside vblank, counting the number
1795  * of scanlines to go until end of vblank, e.g., -1 means "one scanline
1796  * until start of active scanout / end of vblank."
1801  * DRM_SCANOUTPOS_INVBL = Inside vblank.
1879 		/* Pre-AVIVO: Different encoding of scanout pos and vblank interval. */  in radeon_get_crtc_scanoutpos()
1916 	/* Valid vblank area boundaries from gpu retrieved? */  in radeon_get_crtc_scanoutpos()
1929 	/* Called from driver internal vblank counter query code? */  in radeon_get_crtc_scanoutpos()
1935 	/* Fudge vblank to start a few scanlines earlier to handle the  in radeon_get_crtc_scanoutpos()
1936 	 * problem that vblank irqs fire a few scanlines before start  in radeon_get_crtc_scanoutpos()
1937 	 * of vblank. Some driver internal callers need the true vblank  in radeon_get_crtc_scanoutpos()
1940 	 * The cause of the "early" vblank irq is that the irq is triggered  in radeon_get_crtc_scanoutpos()
1942 	 * the vblank, whereas our crtc scanout position naturally lags the  in radeon_get_crtc_scanoutpos()
1948 	/* Test scanout position against vblank region. */  in radeon_get_crtc_scanoutpos()
1952 	/* In vblank? */  in radeon_get_crtc_scanoutpos()
1956 	/* Called from driver internal vblank counter query code? */  in radeon_get_crtc_scanoutpos()
1963 	/* Check if inside vblank area and apply corrective offsets:  in radeon_get_crtc_scanoutpos()
1965 	 * within vblank area, counting down the number of lines until  in radeon_get_crtc_scanoutpos()
1969 	/* Inside "upper part" of vblank area? Apply corrective offset if so: */  in radeon_get_crtc_scanoutpos()