drm/vc4: hdmi: Add more checks for 4k resolutions

At least the 4096x2160@60Hz mode requires some overclocking that isn't
available by default, even if hdmi_enable_4kp60 is enabled.

Let's add some logic to detect whether we can satisfy the core clock
requirements for that mode, and prevent it from being used otherwise.

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220815-rpi-fix-4k-60-v5-6-fe9e7ac8b111@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 8da2b80fdbd3dbebee8dc56881f6a1a589207268..515228682e8e2c35a7a9eacda079e8b58b14aefd 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -347,6 +347,12 @@ struct vc4_hvs {
         * available.
         */
        bool vc5_hdmi_enable_hdmi_20;
+
+       /*
+        * 4096x2160@60 requires a core overclock to work, so register
+        * whether that is sufficient.
+        */
+       bool vc5_hdmi_enable_4096by2160;
 };
 
 struct vc4_plane {

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 3114735df5aea214571e09c5a4a8e3eefecb5096..4a73fafca51b90b42419f9b26f8c583c2005f2c2 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1753,6 +1753,7 @@ vc4_hdmi_sink_supports_format_bpc(const struct vc4_hdmi *vc4_hdmi,
 
 static enum drm_mode_status
 vc4_hdmi_encoder_clock_valid(const struct vc4_hdmi *vc4_hdmi,
+                            const struct drm_display_mode *mode,
                             unsigned long long clock)
 {
        const struct drm_connector *connector = &vc4_hdmi->connector;
@@ -1765,6 +1766,12 @@ vc4_hdmi_encoder_clock_valid(const struct vc4_hdmi *vc4_hdmi,
        if (!vc4->hvs->vc5_hdmi_enable_hdmi_20 && clock > HDMI_14_MAX_TMDS_CLK)
                return MODE_CLOCK_HIGH;
 
+       /* 4096x2160@60 is not reliable without overclocking core */
+       if (!vc4->hvs->vc5_hdmi_enable_4096by2160 &&
+           mode->hdisplay > 3840 && mode->vdisplay >= 2160 &&
+           drm_mode_vrefresh(mode) >= 50)
+               return MODE_CLOCK_HIGH;
+
        if (info->max_tmds_clock && clock > (info->max_tmds_clock * 1000))
                return MODE_CLOCK_HIGH;
 
@@ -1799,7 +1806,7 @@ vc4_hdmi_encoder_compute_clock(const struct vc4_hdmi *vc4_hdmi,
        unsigned long long clock;
 
        clock = vc4_hdmi_encoder_compute_mode_clock(mode, bpc, fmt);
-       if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, clock) != MODE_OK)
+       if (vc4_hdmi_encoder_clock_valid(vc4_hdmi, mode, clock) != MODE_OK)
                return -EINVAL;
 
        vc4_state->tmds_char_rate = clock;
@@ -1962,7 +1969,7 @@ vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder,
             (mode->hsync_end % 2) || (mode->htotal % 2)))
                return MODE_H_ILLEGAL;
 
-       return vc4_hdmi_encoder_clock_valid(vc4_hdmi, mode->clock * 1000);
+       return vc4_hdmi_encoder_clock_valid(vc4_hdmi, mode, mode->clock * 1000);
 }
 
 static const struct drm_encoder_helper_funcs vc4_hdmi_encoder_helper_funcs = {

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index fc4b7310bf6345dac52bfe0fbe43b6c6770b4202..c4453a5ae163ac11758294ec4d8c8ed88d6e1d20 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -818,6 +818,9 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
                if (max_rate >= 550000000)
                        hvs->vc5_hdmi_enable_hdmi_20 = true;
 
+               if (max_rate >= 600000000)
+                       hvs->vc5_hdmi_enable_4096by2160 = true;
+
                hvs->max_core_rate = max_rate;
 
                ret = clk_prepare_enable(hvs->core_clk);