According to the BSP source code, when calculating the magic DRQ value outside burst mode, a formula of "lcd_ht - lcd_x - lcd_hbp", which is interpreted as right margin (HFP value). However, currently the sun6i_mipi_dsi driver code calculates it wrongly as HFP + sync length, which lead to timing error.
Fix the DRQ calculation by change it to use HFP.
Signed-off-by: Icenowy Zheng icenowy@aosc.io --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index c86e11631ebc..2d3e822a7739 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -436,9 +436,9 @@ static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi, SUN6I_DSI_BURST_LINE_SYNC_POINT(SUN6I_DSI_SYNC_POINT));
val = SUN6I_DSI_TCON_DRQ_ENABLE_MODE; - } else if ((mode->hsync_end - mode->hdisplay) > 20) { + } else if ((mode->hsync_start - mode->hdisplay) > 20) { /* Maaaaaagic */ - u16 drq = (mode->hsync_end - mode->hdisplay) - 20; + u16 drq = (mode->hsync_start - mode->hdisplay) - 20;
drq *= mipi_dsi_pixel_format_to_bpp(device->format); drq /= 32;