Re: [PATCH 11/15] drm/sun4i: tcon: Fix tcon channel 1 backporch calculation

From: Chen-Yu Tsai
Date: Tue Mar 07 2017 - 23:34:58 EST


On Tue, Mar 7, 2017 at 4:56 PM, Maxime Ripard
<maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
> It seems like what's called a backporch in the datasheet is actually the
> backporch plus the sync period. Fix that in our driver.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/sun4i/sun4i_tcon.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index 93249c5ab1e4..e44217fb4f6f 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -240,15 +240,14 @@ void sun4i_tcon1_mode_set(struct sun4i_tcon *tcon, struct drm_encoder *encoder,
> SUN4I_TCON1_BASIC2_Y(mode->crtc_vdisplay));
>
> /* Set horizontal display timings */
> - bp = mode->crtc_htotal - mode->crtc_hsync_end;
> + bp = mode->crtc_htotal - mode->crtc_hsync_start;
> DRM_DEBUG_DRIVER("Setting horizontal total %d, backporch %d\n",
> mode->htotal, bp);
> regmap_write(tcon->regs, SUN4I_TCON1_BASIC3_REG,
> SUN4I_TCON1_BASIC3_H_TOTAL(mode->crtc_htotal) |
> SUN4I_TCON1_BASIC3_H_BACKPORCH(bp));
>
> - /* Set vertical display timings */

Why remove the comment?

Otherwise,

Acked-by: Chen-Yu Tsai <wens@xxxxxxxx>

> - bp = mode->crtc_vtotal - mode->crtc_vsync_end;
> + bp = mode->crtc_vtotal - mode->crtc_vsync_start;
> DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n",
> mode->vtotal, bp);
> regmap_write(tcon->regs, SUN4I_TCON1_BASIC4_REG,
> --
> git-series 0.8.11