Leaving this at a close-to-maximum register value 0xFFF0 means it takes very long for the MDSS to generate a software vsync interrupt when the hardware TE interrupt doesn't arrive. Configuring this to double the vtotal (like some downstream kernels) leads to a frame to take at most twice before the vsync signal, until hardware TE comes up. In this case the hardware interrupt responsible for providing this signal - "disp-te" gpio - is not hooked up to the mdp5 vsync/pp logic at all. This solves severe panel update issues observed on at least the Xperia Loire and Tone series, until said gpio is properly hooked up to an irq. Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx> Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx> --- drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c index ff2c1d583c79..2d5ac03dbc17 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_cmd_encoder.c @@ -51,7 +51,7 @@ static int pingpong_tearcheck_setup(struct drm_encoder *encoder, mdp5_write(mdp5_kms, REG_MDP5_PP_SYNC_CONFIG_VSYNC(pp_id), cfg); mdp5_write(mdp5_kms, - REG_MDP5_PP_SYNC_CONFIG_HEIGHT(pp_id), 0xfff0); + REG_MDP5_PP_SYNC_CONFIG_HEIGHT(pp_id), (2 * mode->vtotal)); mdp5_write(mdp5_kms, REG_MDP5_PP_VSYNC_INIT_VAL(pp_id), mode->vdisplay); mdp5_write(mdp5_kms, REG_MDP5_PP_RD_PTR_IRQ(pp_id), mode->vdisplay + 1); -- 2.31.1
