[PATCH 06/17] drm/tegra: dc: Add missing call to drm_vblank_on()

[Sean Paul]

On Mon, Nov 3, 2014 at 4:27 AM, Thierry Reding <thierry.reding at gmail.com> wrote:
> From: Thierry Reding <treding at nvidia.com>
>
> When the CRTC is enabled, make sure the VBLANK machinery is enabled.
> Failure to do so will cause drm_vblank_get() to not enable the VBLANK on
> the CRTC and VBLANK-synchronized page-flips won't work.
>
> While at it, get rid of the legacy drm_vblank_pre_modeset() and
> drm_vblank_post_modeset() calls that are replaced by drm_vblank_on()
> and drm_vblank_off().
>
> Reported-by: Alexandre Courbot <acourbot at nvidia.com>
> Signed-off-by: Thierry Reding <treding at nvidia.com>
> ---
>  drivers/gpu/drm/tegra/dc.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
> index 4a015232e2e8..4da366a4d78a 100644
> --- a/drivers/gpu/drm/tegra/dc.c
> +++ b/drivers/gpu/drm/tegra/dc.c
> @@ -739,7 +739,6 @@ static const struct drm_crtc_funcs tegra_crtc_funcs = {
>
>  static void tegra_crtc_disable(struct drm_crtc *crtc)
>  {
> -       struct tegra_dc *dc = to_tegra_dc(crtc);
>         struct drm_device *drm = crtc->dev;
>         struct drm_plane *plane;
>
> @@ -755,7 +754,7 @@ static void tegra_crtc_disable(struct drm_crtc *crtc)
>                 }
>         }
>
> -       drm_vblank_off(drm, dc->pipe);
> +       drm_crtc_vblank_off(crtc);
>  }
>
>  static bool tegra_crtc_mode_fixup(struct drm_crtc *crtc,
> @@ -844,8 +843,6 @@ static int tegra_crtc_mode_set(struct drm_crtc *crtc,
>         u32 value;
>         int err;
>
> -       drm_vblank_pre_modeset(crtc->dev, dc->pipe);
> -

Should you replace this with a call to drm_crtc_vblank_off in
prepare()? AFAICT, crtc_funcs->disable() isn't guaranteed to be called
before modeset, and it's unclear to me whether the vblank counter will
be reset in prepare.

Sean



>         err = tegra_crtc_setup_clk(crtc, mode);
>         if (err) {
>                 dev_err(dc->dev, "failed to setup clock for CRTC: %d\n", err);
> @@ -946,7 +943,7 @@ static void tegra_crtc_commit(struct drm_crtc *crtc)
>         value = GENERAL_ACT_REQ | WIN_A_ACT_REQ;
>         tegra_dc_writel(dc, value, DC_CMD_STATE_CONTROL);
>
> -       drm_vblank_post_modeset(crtc->dev, dc->pipe);
> +       drm_crtc_vblank_on(crtc);
>  }
>
>  static void tegra_crtc_load_lut(struct drm_crtc *crtc)
> --
> 2.1.2
>