From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jagan Teki Subject: [PATCH v7 22/23] drm/sun4i: sun6i_mipi_dsi: Fix DSI hfp timing value Date: Fri, 1 Feb 2019 21:12:31 +0530 Message-ID: <20190201154232.10505-23-jagan@amarulasolutions.com> References: <20190201154232.10505-1-jagan@amarulasolutions.com> Reply-To: jagan-dyjBcgdgk7Pe9wHmmfpqLFaTQe2KTcn/@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org In-Reply-To: <20190201154232.10505-1-jagan-dyjBcgdgk7Pe9wHmmfpqLFaTQe2KTcn/@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Maxime Ripard , David Airlie , Daniel Vetter , Chen-Yu Tsai , Michael Turquette , Rob Herring , Mark Rutland Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michael Trimarchi , linux-amarula-dyjBcgdgk7Pe9wHmmfpqLFaTQe2KTcn/@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Jagan Teki List-Id: devicetree@vger.kernel.org Current driver is calculating hfp maximum value by subtracting htotal with hsync_end which is front back value, but the hpp refers to front porch. Front porch value is calculating by subtracting hsync_start with hdisplay as per drm_mode timings, and BSP code from BPI-M64-bsp is eventually following the same. BPI-M64-bsp is computing hfp as (from linux-sunxi/ drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c) dsi_hbp = (hbp-hspw)*dsi_pixel_bits[format]/8 - (4+2); dsi_hact = x * dsi_pixel_bits[format]/8; dsi_hblk = (ht-hspw)*dsi_pixel_bits[format]/8-(4+4+2); dsi_hfp = dsi_hblk - (4+dsi_hact+2) - (4+dsi_hbp+2); Example, u32 fmt = dsi_pixel_bits[format]/8; => ((ht-hspw)*fmt - 10) - (6 + x * fmt) - (6 + (hbp-hspw)*fmt - 6) => (ht - hspw - x - (hbp - hspw)) * fmt - 16 => (ht - x - hbp) * fmt - 16 => (ht - x - (timmings->hor_total_time - timmings->hor_front_porch - x) * fmt - 16 => (timmings->hor_total_time - x - timmings->hor_total_time + timmings->hor_front_porch + x) * fmt - 16 => timmings->hor_front_porch * fmt - 16 So, update the DSI hfp timing accordingly. Tested on 2-lane, 4-lane MIPI-DSI LCD panels. Signed-off-by: Jagan Teki Tested-by: Merlijn Wajer --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 780b1906c661..3fbe2132eb6a 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -587,7 +587,8 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, */ #define HFP_PACKET_OVERHEAD 6 hfp = max((unsigned int)HFP_PACKET_OVERHEAD, - (mode->htotal - mode->hsync_end) * Bpp - HFP_PACKET_OVERHEAD); + (mode->hsync_start - mode->hdisplay) * Bpp - + HFP_PACKET_OVERHEAD); /* * hblk seems to be the line + porches length. -- 2.18.0.321.gffc6fa0e3