From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jagan Teki Subject: [PATCH v6 20/22] drm/sun4i: sun6i_mipi_dsi: Fix DSI hbp timing value Date: Fri, 25 Jan 2019 01:28:58 +0530 Message-ID: <20190124195900.22620-21-jagan@amarulasolutions.com> References: <20190124195900.22620-1-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: <20190124195900.22620-1-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 hbp maximum value by subtracting hsync_start with hdisplay which is front porch value, but the hbp refers to back porch. Back porch value is calculating by subtracting htotal with hsync_end as per drm_mode timings, and BSP code from BPI-M64-bsp is eventually following the same. BPI-M64-bsp is computing hbp as (in drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c) dsi_hbp = (hbp-hspw)*dsi_pixel_bits[format]/8 - (4+2); => (panel->lcd_hbp - timmings->hor_sync_time) => (timmings->hor_back_porch + timmings->hor_sync_time - timmings->hor_sync_time) => timmings->hor_back_porch => mode->htotal - mode->hsync_end So, update the MIPI-DSI hbp value accordingly. Tested on 2-lane, 4-lane DSI LCD panels. Signed-off-by: Jagan Teki --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 58bda0928aef..e24719cabba2 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -578,7 +578,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, */ #define HBP_PACKET_OVERHEAD 6 hbp = max((unsigned int)HBP_PACKET_OVERHEAD, - (mode->hsync_start - mode->hdisplay) * Bpp - HBP_PACKET_OVERHEAD); + (mode->htotal - mode->hsync_end) * Bpp - HBP_PACKET_OVERHEAD); /* * The frontporch is set using a blanking packet (4 bytes + -- 2.18.0.321.gffc6fa0e3