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

Message ID 59bdbadc4d3adc6d75c2cef38df0af332bd313db.1493812478.git-series.maxime.ripard@free-electrons.com (mailing list archive)
State Superseded
Headers show

Commit Message

Maxime Ripard May 3, 2017, 11:59 a.m. UTC
It appears that the total vertical resolution needs to be doubled when
we're not in interlaced. Make sure that is the case.

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(-)

Comments

Chen-Yu Tsai May 4, 2017, 4:07 a.m. UTC | #1
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
--
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Icenowy Zheng May 5, 2017, 8:16 a.m. UTC | #2
在 2017-05-03 19:59,Maxime Ripard 写道:
> It appears that the total vertical resolution needs to be doubled when
> we're not in interlaced. Make sure that is the case.
> 
> 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) |

For TVE the value should directly be mode->vtotal, but not
mode->crtc_vtotal * 2.

vtotal is 625 when PAL. crtc_vtotal is thus 312, but if we restore the
vtotal value by doubling crtv_vtotal, we got 624, which will lead to
instability of the image displayed. (the image will loop to go higher
and then go lower, because wrong vtotal value)

Tested on patched H3 TV encoder.

I used a logic slightly changed from your v1 code:

```
	val = mode->vtotal;
	if (!(mode->flags & DRM_MODE_FLAG_INTERLACE))
		val = val * 2;
	regmap_write(tcon->regs, SUN4I_TCON1_BASIC4_REG,
		     SUN4I_TCON1_BASIC4_V_TOTAL(val) |
		     SUN4I_TCON1_BASIC4_V_BACKPORCH(bp));
```

>  		     SUN4I_TCON1_BASIC4_V_BACKPORCH(bp));
> 
>  	/* Set Hsync and Vsync length */
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diff mbox

Patch

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 */