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

From: Chen-Yu Tsai
Date: Thu May 04 2017 - 00:08:33 EST


On Wed, May 3, 2017 at 7:59 PM, Maxime Ripard
<maxime.ripard@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx>
> ---
> 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