Like other dsi setup timings, hblk would also require to add packet overhead. Add 10 bytes packet overhead for hblk, so the blank is set using a blanking packet like (4 bytes + 4 bytes + payload + 2 bytes) The value 10 bytes are refereed from Allwinner BSP like how other dsi setup timings grabs in existing driver. This is according to BSP code from BPI-M64-bsp (from linux-sunxi/ drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c) dsi_hblk = (ht-hspw)*dsi_pixel_bits[format]/8-(4+4+2); So, add 10 bytes packet overhead for DSI hblk. Tested on 2-lane, 4-lane MIPI-DSI LCD panels. Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 6b26dba883e8..a64e6ec00f22 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -485,8 +485,13 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, /* * hblk seems to be the line + porches length. + * The blank is set using a blanking packet (4 bytes + 4 bytes + + * payload + 2 bytes). So minimal size is 10 bytes */ - hblk = (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp; +#define HBLK_PACKET_OVERHEAD 10 + hblk = max((unsigned int)HBLK_PACKET_OVERHEAD, + (mode->htotal - (mode->hsync_end - mode->hsync_start)) * + Bpp - HBLK_PACKET_OVERHEAD); /* * And I'm not entirely sure what vblk is about. The driver in -- 2.18.0.321.gffc6fa0e3 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel