Re: [PATCH v2 14/20] drm/sun4i: tcon: multiply the vtotal when not in interlace

From	Chen-Yu Tsai <wens@csie.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 14/20] drm/sun4i: tcon: multiply the vtotal when not in interlace
Date	2017-05-04 06:10 +0200
Message-ID	<tDgfv-6HS-1@gated-at.bofh.it> (permalink)
References	<tD1gu-5a8-5@gated-at.bofh.it> <tD1gu-5a8-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, May 3, 2017 at 7:59 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> It appears that the total vertical resolution needs to be doubled when
> we're not in interlaced. Make sure that is the case.

I think the total vertical resolution needs to be doubled in all cases.
It just happens that you should've been using mode->crtc_vtotal, which
is halved when the mode is interlaced. Instead you used mode->vtotal,
which is double the actual scan resolution in interlaced mode.

ChenYu

> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_tcon.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index 0f91ec8a4b26..efa079c1a3f5 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -272,9 +272,9 @@ void sun4i_tcon1_mode_set(struct sun4i_tcon *tcon,
>         /* Set vertical display timings */
>         bp = mode->crtc_vtotal - mode->crtc_vsync_start;
>         DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n",
> -                        mode->vtotal, bp);
> +                        mode->crtc_vtotal, bp);
>         regmap_write(tcon->regs, SUN4I_TCON1_BASIC4_REG,
> -                    SUN4I_TCON1_BASIC4_V_TOTAL(mode->vtotal) |
> +                    SUN4I_TCON1_BASIC4_V_TOTAL(mode->crtc_vtotal * 2) |
>                      SUN4I_TCON1_BASIC4_V_BACKPORCH(bp));
>
>         /* Set Hsync and Vsync length */
> --
> git-series 0.8.11

Thread

[PATCH v2 14/20] drm/sun4i: tcon: multiply the vtotal when not in interlace Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-03 14:10 +0200
  Re: [PATCH v2 14/20] drm/sun4i: tcon: multiply the vtotal when not in interlace Chen-Yu Tsai <wens@csie.org> - 2017-05-04 06:10 +0200
  Re: [PATCH v2 14/20] drm/sun4i: tcon: multiply the vtotal when not in  interlace icenowy@aosc.io - 2017-05-05 10:20 +0200

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