From 7fe3f0d15aac6c98a97e6d7086f5a6b7bc4ccae4 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Thu, 23 Jan 2020 14:59:24 +0100 Subject: drm: Add get_vblank_timestamp() to struct drm_crtc_funcs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The callback get_vblank_timestamp() is currently located in struct drm_driver, but really belongs into struct drm_crtc_funcs. Add an equivalent there. Driver will be converted in separate patches. The default implementation is drm_calc_vbltimestamp_from_scanoutpos(). The patch adds drm_crtc_vblank_helper_get_vblank_timestamp(), which is an implementation for the CRTC callback. v4: * more readable code for setting high_prec (Ville, Jani) v3: * use refactored timestamp calculation to minimize duplicated code * do more checks for crtc != NULL to support legacy drivers v2: * rename helper to drm_crtc_vblank_helper_get_vblank_timestamp() * replace drm_calc_vbltimestamp_from_scanoutpos() with drm_crtc_vblank_helper_get_vblank_timestamp() in docs Signed-off-by: Thomas Zimmermann Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200123135943.24140-4-tzimmermann@suse.de --- include/drm/drm_crtc.h | 46 ++++++++++++++++++++++++++++++-- include/drm/drm_modeset_helper_vtables.h | 4 +-- include/drm/drm_vblank.h | 16 ++++++++--- 3 files changed, 58 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 6bef2f41d4d7..59b51a09cae6 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -887,6 +887,47 @@ struct drm_crtc_funcs { * new drivers as the replacement of &drm_driver.disable_vblank hook. */ void (*disable_vblank)(struct drm_crtc *crtc); + + /** + * @get_vblank_timestamp: + * + * Called by drm_get_last_vbltimestamp(). Should return a precise + * timestamp when the most recent vblank interval ended or will end. + * + * Specifically, the timestamp in @vblank_time should correspond as + * closely as possible to the time when the first video scanline of + * the video frame after the end of vblank will start scanning out, + * the time immediately after end of the vblank interval. If the + * @crtc is currently inside vblank, this will be a time in the future. + * If the @crtc is currently scanning out a frame, this will be the + * past start time of the current scanout. This is meant to adhere + * to the OpenML OML_sync_control extension specification. + * + * Parameters: + * + * crtc: + * CRTC for which timestamp should be returned. + * max_error: + * Maximum allowable timestamp error in nanoseconds. + * Implementation should strive to provide timestamp + * with an error of at most max_error nanoseconds. + * Returns true upper bound on error for timestamp. + * vblank_time: + * Target location for returned vblank timestamp. + * in_vblank_irq: + * True when called from drm_crtc_handle_vblank(). Some drivers + * need to apply some workarounds for gpu-specific vblank irq quirks + * if flag is set. + * + * Returns: + * + * True on success, false on failure, which means the core should + * fallback to a simple timestamp taken in drm_crtc_handle_vblank(). + */ + bool (*get_vblank_timestamp)(struct drm_crtc *crtc, + int *max_error, + ktime_t *vblank_time, + bool in_vblank_irq); }; /** @@ -994,11 +1035,12 @@ struct drm_crtc { * Programmed mode in hw, after adjustments for encoders, crtc, panel * scaling etc. Should only be used by legacy drivers, for high * precision vblank timestamps in - * drm_calc_vbltimestamp_from_scanoutpos(). + * drm_crtc_vblank_helper_get_vblank_timestamp(). * * Note that atomic drivers should not use this, but instead use * &drm_crtc_state.adjusted_mode. And for high-precision timestamps - * drm_calc_vbltimestamp_from_scanoutpos() used &drm_vblank_crtc.hwmode, + * drm_crtc_vblank_helper_get_vblank_timestamp() used + * &drm_vblank_crtc.hwmode, * which is filled out by calling drm_calc_timestamping_constants(). */ struct drm_display_mode hwmode; diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index e398512bfd5f..0afaf58da40d 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -459,8 +459,8 @@ struct drm_crtc_helper_funcs { * Returns the current display scanout position from a CRTC and an * optional accurate ktime_get() timestamp of when the position was * measured. Note that this is a helper callback which is only used - * if a driver uses drm_calc_vbltimestamp_from_scanoutpos() for the - * @drm_driver.get_vblank_timestamp callback. + * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() + * for the @drm_crtc_funcs.get_vblank_timestamp callback. * * Parameters: * diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h index fd28741e64ed..91f8e35d588d 100644 --- a/include/drm/drm_vblank.h +++ b/include/drm/drm_vblank.h @@ -174,13 +174,13 @@ struct drm_vblank_crtc { unsigned int pipe; /** * @framedur_ns: Frame/Field duration in ns, used by - * drm_calc_vbltimestamp_from_scanoutpos() and computed by + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by * drm_calc_timestamping_constants(). */ int framedur_ns; /** * @linedur_ns: Line duration in ns, used by - * drm_calc_vbltimestamp_from_scanoutpos() and computed by + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by * drm_calc_timestamping_constants(). */ int linedur_ns; @@ -190,8 +190,8 @@ struct drm_vblank_crtc { * * Cache of the current hardware display mode. Only valid when @enabled * is set. This is used by helpers like - * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the - * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, + * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access + * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, * because that one is really hard to get from interrupt context. */ struct drm_display_mode hwmode; @@ -240,6 +240,10 @@ wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, u32 max_vblank_count); +/* + * Helpers for struct drm_crtc_funcs + */ + typedef bool (*drm_vblank_get_scanout_position_func)(struct drm_crtc *crtc, bool in_vblank_irq, int *vpos, int *hpos, @@ -263,5 +267,9 @@ drm_crtc_vblank_helper_get_vblank_timestamp_internal(struct drm_crtc *crtc, bool in_vblank_irq, drm_vblank_get_scanout_position_func get_scanout_position, drm_vblank_get_scanout_position_legacy_func get_scanout_position_legacy); +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, + int *max_error, + ktime_t *vblank_time, + bool in_vblank_irq); #endif -- cgit v1.2.3