On Fri, 10 Jan 2020, Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:
> The new callback get_scanout_position() reads the current location of
> the scanout process. The operation is currentyl located in struct
> drm_driver, but really belongs to the CRTC. Drivers will be converted
> in separate patches.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
> drivers/gpu/drm/drm_vblank.c | 24 ++++++++----
> include/drm/drm_drv.h | 7 +---
> include/drm/drm_modeset_helper_vtables.h | 47 ++++++++++++++++++++++++
> 3 files changed, 65 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index 1659b13b178c..c12f0b333e14 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -30,6 +30,7 @@
> #include <drm/drm_crtc.h>
> #include <drm/drm_drv.h>
> #include <drm/drm_framebuffer.h>
> +#include <drm/drm_modeset_helper_vtables.h>
> #include <drm/drm_print.h>
> #include <drm/drm_vblank.h>
>
> @@ -590,7 +591,7 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants);
> * Implements calculation of exact vblank timestamps from given drm_display_mode
> * timings and current video scanout position of a CRTC. This can be directly
> * used as the &drm_driver.get_vblank_timestamp implementation of a kms driver
> - * if &drm_driver.get_scanout_position is implemented.
> + * if &drm_crtc_helper_funcs.get_scanout_position is implemented.
> *
> * The current implementation only handles standard video modes. For double scan
> * and interlaced modes the driver is supposed to adjust the hardware mode
> @@ -632,8 +633,9 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
> }
>
> /* Scanout position query not supported? Should not happen. */
> - if (!dev->driver->get_scanout_position) {
> - DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
> + if (!dev->driver->get_scanout_position ||
> + !crtc->helper_private->get_scanout_position) {
ITYM s/||/&&/
BR,
Jani.
> + DRM_ERROR("Called from CRTC w/o get_scanout_position()!?\n");
> return false;
> }
>
> @@ -664,11 +666,17 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
> * Get vertical and horizontal scanout position vpos, hpos,
> * and bounding timestamps stime, etime, pre/post query.
> */
> - vbl_status = dev->driver->get_scanout_position(dev, pipe,
> - in_vblank_irq,
> - &vpos, &hpos,
> - &stime, &etime,
> - mode);
> + if (crtc->helper_private->get_scanout_position) {
> + vbl_status =
> + crtc->helper_private->get_scanout_position(
> + crtc, in_vblank_irq, &vpos, &hpos,
> + &stime, &etime, mode);
> + } else {
> + vbl_status =
> + dev->driver->get_scanout_position(
> + dev, pipe, in_vblank_irq, &vpos,
> + &hpos, &stime, &etime, mode);
> + }
>
> /* Return as no-op if scanout query unsupported or failed. */
> if (!vbl_status) {
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index cf13470810a5..d0049e5786fc 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -362,11 +362,8 @@ struct drm_driver {
> * True on success, false if a reliable scanout position counter could
> * not be read out.
> *
> - * FIXME:
> - *
> - * Since this is a helper to implement @get_vblank_timestamp, we should
> - * move it to &struct drm_crtc_helper_funcs, like all the other
> - * helper-internal hooks.
> + * This is deprecated and should not be used by new drivers.
> + * Use &drm_crtc_helper_funcs.get_scanout_position instead.
> */
> bool (*get_scanout_position) (struct drm_device *dev, unsigned int pipe,
> bool in_vblank_irq, int *vpos, int *hpos,
> diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
> index 5a87f1bd7a3f..e398512bfd5f 100644
> --- a/include/drm/drm_modeset_helper_vtables.h
> +++ b/include/drm/drm_modeset_helper_vtables.h
> @@ -450,6 +450,53 @@ struct drm_crtc_helper_funcs {
> */
> void (*atomic_disable)(struct drm_crtc *crtc,
> struct drm_crtc_state *old_crtc_state);
> +
> + /**
> + * @get_scanout_position:
> + *
> + * Called by vblank timestamping code.
> + *
> + * 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.
> + *
> + * Parameters:
> + *
> + * crtc:
> + * The CRTC.
> + * 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 the flag is set.
> + * vpos:
> + * Target location for current vertical scanout position.
> + * hpos:
> + * Target location for current horizontal scanout position.
> + * stime:
> + * Target location for timestamp taken immediately before
> + * scanout position query. Can be NULL to skip timestamp.
> + * etime:
> + * Target location for timestamp taken immediately after
> + * scanout position query. Can be NULL to skip timestamp.
> + * mode:
> + * Current display timings.
> + *
> + * Returns vpos as a positive number while in active scanout area.
> + * Returns vpos as a negative number inside vblank, counting the number
> + * of scanlines to go until end of vblank, e.g., -1 means "one scanline
> + * until start of active scanout / end of vblank."
> + *
> + * Returns:
> + *
> + * True on success, false if a reliable scanout position counter could
> + * not be read out.
> + */
> + bool (*get_scanout_position)(struct drm_crtc *crtc,
> + bool in_vblank_irq, int *vpos, int *hpos,
> + ktime_t *stime, ktime_t *etime,
> + const struct drm_display_mode *mode);
> };
>
> /**
--
Jani Nikula, Intel Open Source Graphics Center
