[PATCH] drm/msm/mdp5: Always generate active-high sync signals for DSI

[Hai Li <hali@codeaurora.org>]

DSI video mode engine can only take active-high sync signals. This
change prevents MDP5 sending active-low sync signals to DSI in any
case.

Signed-off-by: Hai Li <hali@codeaurora.org>
---
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
index 53bb1f7..2e98ce0 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
@@ -144,10 +144,14 @@ static void mdp5_encoder_mode_set(struct drm_encoder *encoder,
 			mode->type, mode->flags);
 
 	ctrl_pol = 0;
-	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
-		ctrl_pol |= MDP5_INTF_POLARITY_CTL_HSYNC_LOW;
-	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
-		ctrl_pol |= MDP5_INTF_POLARITY_CTL_VSYNC_LOW;
+
+	/* DSI controller cannot handle active-low sync signals. */
+	if (mdp5_encoder->intf.type != INTF_DSI) {
+		if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+			ctrl_pol |= MDP5_INTF_POLARITY_CTL_HSYNC_LOW;
+		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+			ctrl_pol |= MDP5_INTF_POLARITY_CTL_VSYNC_LOW;
+	}
 	/* probably need to get DATA_EN polarity from panel.. */
 
 	dtv_hsync_skew = 0;  /* get this from panel? */
-- 
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