The driver has a few places where it does: if (thing_is_enabled_in_config) update_thing_bit_in_hw() This means that if the thing is _not_ enabled, the bit never gets cleared. This affects the h/vsyncs and continuous DSI clock bits. Fix the driver to always update the bit. Fixes: ff1ca6397b1d ("drm/bridge: Add tc358768 driver") Reviewed-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx> Tested-by: Maxim Schwalm <maxim.schwalm@xxxxxxxxx> # Asus TF700T Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx> --- drivers/gpu/drm/bridge/tc358768.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c index 963ac550509b..99992af23f1e 100644 --- a/drivers/gpu/drm/bridge/tc358768.c +++ b/drivers/gpu/drm/bridge/tc358768.c @@ -794,8 +794,8 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge) val |= BIT(i + 1); tc358768_write(priv, TC358768_HSTXVREGEN, val); - if (!(mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS)) - tc358768_write(priv, TC358768_TXOPTIONCNTRL, 0x1); + tc358768_write(priv, TC358768_TXOPTIONCNTRL, + (mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) ? 0 : BIT(0)); /* TXTAGOCNT[26:16] RXTASURECNT[10:0] */ val = tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk * 4); @@ -861,11 +861,12 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge) tc358768_write(priv, TC358768_DSI_HACT, hact); /* VSYNC polarity */ - if (!(mode->flags & DRM_MODE_FLAG_NVSYNC)) - tc358768_update_bits(priv, TC358768_CONFCTL, BIT(5), BIT(5)); + tc358768_update_bits(priv, TC358768_CONFCTL, BIT(5), + (mode->flags & DRM_MODE_FLAG_PVSYNC) ? BIT(5) : 0); + /* HSYNC polarity */ - if (mode->flags & DRM_MODE_FLAG_PHSYNC) - tc358768_update_bits(priv, TC358768_PP_MISC, BIT(0), BIT(0)); + tc358768_update_bits(priv, TC358768_PP_MISC, BIT(0), + (mode->flags & DRM_MODE_FLAG_PHSYNC) ? BIT(0) : 0); /* Start DSI Tx */ tc358768_write(priv, TC358768_DSI_START, 0x1); -- 2.34.1