[PATCH 12/15] drm/sun4i: tcon: multiply the vtotal when not in interlace
maxime.ripard at free-electrons.com
Thu Mar 9 02:54:50 PST 2017
On Tue, Mar 07, 2017 at 06:05:17PM +0800, Chen-Yu Tsai wrote:
> On Tue, Mar 7, 2017 at 4:56 PM, Maxime Ripard
> <maxime.ripard at 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.
> This is true for both channels, though we handle them differently.
> > Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
> > ---
> > drivers/gpu/drm/sun4i/sun4i_tcon.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > index e44217fb4f6f..515fa56c1e6a 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > @@ -248,10 +248,13 @@ void sun4i_tcon1_mode_set(struct sun4i_tcon *tcon, struct drm_encoder *encoder,
> > SUN4I_TCON1_BASIC3_H_BACKPORCH(bp));
> > bp = mode->crtc_vtotal - mode->crtc_vsync_start;
> > + val = mode->crtc_vtotal;
> > + if (!(mode->flags & DRM_MODE_FLAG_INTERLACE))
> > + val = val * 2;
> > DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n",
> > mode->vtotal, bp);
> > regmap_write(tcon->regs, SUN4I_TCON1_BASIC4_REG,
> > - SUN4I_TCON1_BASIC4_V_TOTAL(mode->vtotal) |
> > + SUN4I_TCON1_BASIC4_V_TOTAL(val) |
> For channel 0, the SUN4I_TCON0_BASIC2_V_TOTAL macro multiplies the passed in
> value by 2. I think we should do the same for channel 1, and instead halve the
> value passed in if we are outputting interlaced data. I think this makes more
> sense because:
> 1) The register description for both channels are the same. Handling them
> consistently will result in less confusion, such as this one.
> 2) The definition of interlaced modes is a frame is separated into odd and
> even fields, with each field contains half the number of lines of the
> full frame. One field is displayed during each VSYNC cycle. The TCON does
> not know whether it's interlaced video or not. It only knows the display
> timings. In this case, the number of horizontal lines per cycle is key.
Hmm, yes, you're right. I'll fix it in the next release.
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
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