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[v5,09/17] drm/sun4i: sun6i_mipi_dsi: Fix DSI hblk timing calculation

Message ID 20181210161729.29720-10-jagan@amarulasolutions.com (mailing list archive)
State New, archived
Headers show
Series drm/sun4i: Allwinner A64 MIPI-DSI support | expand

Commit Message

Jagan Teki Dec. 10, 2018, 4:17 p.m. UTC 
hblk is adding line with all porch timing values, or timings
values from htotal without sync time.

Current driver is subtracting htotal with hsa, but the hsa
is bounded with packet overhead. For real hblk calculation
needed by subtracting htotal with back and front porch values
and BSP code BPI-M64-bsp is eventually following the same.

BPI-M64-bsp is computing hbp as (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);
=> (timmings->hor_total_time - timmings->hor_sync_time)
=> (mode->htotal - (mode->hsync_end - mode->hsync_start))

So, update the DSI hblk timing accordingly.

Tested on 2-lane, 4-lane MIPI-DSI LCD panels.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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Patch

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 81151d7633f9..4c95b3384ed9 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -495,7 +495,7 @@  static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
 	/*
 	 * hblk seems to be the line + porches length.
 	 */
-	hblk = mode->htotal * Bpp - hsa;
+	hblk = (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp;
 
 	/*
 	 * And I'm not entirely sure what vblk is about. The driver in