The max() function call in horizontal timing calculation shouldn't pad a length already subtracted with overhead to overhead, instead it should only prevent the set timing to underflow. Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx> --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 059939789730..5f2313c40328 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -555,7 +555,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, */ #define HSA_PACKET_OVERHEAD 10 hsa = max((unsigned int)HSA_PACKET_OVERHEAD, - (mode->hsync_end - mode->hsync_start) * Bpp - HSA_PACKET_OVERHEAD); + (mode->hsync_end - mode->hsync_start) * Bpp) - HSA_PACKET_OVERHEAD; /* * The backporch is set using a blanking packet (4 @@ -564,7 +564,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, */ #define HBP_PACKET_OVERHEAD 6 hbp = max((unsigned int)HBP_PACKET_OVERHEAD, - (mode->htotal - mode->hsync_end) * Bpp - HBP_PACKET_OVERHEAD); + (mode->htotal - mode->hsync_end) * Bpp) - HBP_PACKET_OVERHEAD; /* * The frontporch is set using a sync event (4 bytes) @@ -574,7 +574,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, */ #define HFP_PACKET_OVERHEAD 16 hfp = max((unsigned int)HFP_PACKET_OVERHEAD, - (mode->hsync_start - mode->hdisplay) * Bpp - HFP_PACKET_OVERHEAD); + (mode->hsync_start - mode->hdisplay) * Bpp) - HFP_PACKET_OVERHEAD; /* * The blanking is set using a sync event (4 bytes) @@ -583,8 +583,8 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi, */ #define HBLK_PACKET_OVERHEAD 10 hblk = max((unsigned int)HBLK_PACKET_OVERHEAD, - (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp - - 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 -- 2.24.1
