From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753518AbdEQJvN (ORCPT ); Wed, 17 May 2017 05:51:13 -0400 Received: from smtp.csie.ntu.edu.tw ([140.112.30.61]:52214 "EHLO smtp.csie.ntu.edu.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753366AbdEQJvK (ORCPT ); Wed, 17 May 2017 05:51:10 -0400 MIME-Version: 1.0 In-Reply-To: References: From: Chen-Yu Tsai Date: Wed, 17 May 2017 17:50:45 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3 14/21] drm/sun4i: tcon: multiply the vtotal when not in interlace To: Maxime Ripard Cc: Chen-Yu Tsai , Mike Turquette , Stephen Boyd , Daniel Vetter , David Airlie , dri-devel , linux-clk , linux-arm-kernel , devicetree , linux-kernel , Thomas Petazzoni Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 17, 2017 at 3:40 PM, Maxime Ripard wrote: > 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 > --- > drivers/gpu/drm/sun4i/sun4i_tcon.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c > index 62e254aedb57..a0f9a8a516c7 100644 > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c > @@ -153,7 +153,7 @@ static int sun4i_tcon_get_clk_delay(struct drm_display_mode *mode, > void sun4i_tcon0_mode_set(struct sun4i_tcon *tcon, > struct drm_display_mode *mode) > { > - unsigned int bp, hsync, vsync; > + unsigned int bp, hsync, vsync, vtotal; > u8 clk_delay; > u32 val = 0; > > @@ -192,9 +192,26 @@ void sun4i_tcon0_mode_set(struct sun4i_tcon *tcon, > DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n", > mode->crtc_vtotal, bp); > > + /* > + * The vertical resolution needs to be doubled in all > + * cases. We could use crtc_vtotal and always multiply by two, > + * but that leads to a rounding error in interlace when vtotal > + * is odd. > + * > + * This happens with TV's PAL for example, where vtotal will > + * be 625, crtc_vtotal 312, and thus crtc_vtotal * 2 will be > + * 624, which apparently confuses the hardware. > + * > + * To work around this, we will always use vtotal, and > + * multiply by two only if we're not in interlace. > + */ > + vtotal = mode->vtotal; > + if (!(mode->flags & DRM_MODE_FLAG_INTERLACE)) > + vtotal = vtotal * 2; > + > /* Set vertical display timings */ > regmap_write(tcon->regs, SUN4I_TCON0_BASIC2_REG, > - SUN4I_TCON0_BASIC2_V_TOTAL(mode->crtc_vtotal * 2) | > + SUN4I_TCON0_BASIC2_V_TOTAL(vtotal) | > SUN4I_TCON0_BASIC2_V_BACKPORCH(bp)); > > /* Set Hsync and Vsync length */ > @@ -279,9 +296,9 @@ 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); You should duplicate the logic from channel 0 to channel 1. In fact, interlaced modes happen predominantly on channel 1, for composite and HDMI modes. ChenYu > 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 0.9.1