From 247a631f9c0ffb37ed0786a94cb4c5f2b6fc7ab1 Mon Sep 17 00:00:00 2001 From: Dom Cobley Date: Fri, 27 Jan 2023 15:55:58 +0100 Subject: [PATCH] drm/vc4: crtc: Increase setup cost in core clock calculation to handle extreme reduced blanking The formula that determines the core clock requirement based on pixel clock and blanking has been determined experimentally to minimise the clock while supporting all modes we've seen. A new reduced blanking mode (4kp60 at 533MHz rather than the standard 594MHz) has been seen that doesn't produce a high enough clock and results in "flip_done timed out" error. Increase the setup cost in the formula to make this work. The result is a reduced blanking mode increases by up to 7MHz while leaving the standard timing mode untouched Link: https://github.com/raspberrypi/linux/issues/4446 Fixes: 16e101051f32 ("drm/vc4: Increase the core clock based on HVS load") Signed-off-by: Dom Cobley Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20230127145558.446123-1-maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_crtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index 0108613e79d5..7258975331ca 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -711,7 +711,7 @@ static int vc4_crtc_atomic_check(struct drm_crtc *crtc, struct vc4_encoder *vc4_encoder = to_vc4_encoder(encoder); if (vc4_encoder->type == VC4_ENCODER_TYPE_HDMI0) { - vc4_state->hvs_load = max(mode->clock * mode->hdisplay / mode->htotal + 1000, + vc4_state->hvs_load = max(mode->clock * mode->hdisplay / mode->htotal + 8000, mode->clock * 9 / 10) * 1000; } else { vc4_state->hvs_load = mode->clock * 1000;