In order to reach the frequencies needed to output at 594MHz, the firmware needs to be configured with the appropriate parameters in the config.txt file (enable_hdmi_4kp60 and force_turbo). Let's detect it at bind time, warn the user if we can't, and filter out the relevant modes. Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> --- drivers/gpu/drm/vc4/vc4_hdmi.c | 31 +++++++++++++++++++++++++++++++ drivers/gpu/drm/vc4/vc4_hdmi.h | 8 ++++++++ 2 files changed, 39 insertions(+) diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index c50dc5a59b2f..01d24ce8a795 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -94,6 +94,11 @@ #define HDMI_14_MAX_TMDS_CLK (340 * 1000 * 1000) +static bool vc4_hdmi_mode_needs_scrambling(const struct drm_display_mode *mode) +{ + return (mode->clock * 1000) > HDMI_14_MAX_TMDS_CLK; +} + static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused) { struct drm_info_node *node = (struct drm_info_node *)m->private; @@ -210,6 +215,18 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector) ret = drm_add_edid_modes(connector, edid); kfree(edid); + if (vc4_hdmi->disable_4kp60) { + struct drm_device *drm = connector->dev; + struct drm_display_mode *mode; + + list_for_each_entry(mode, &connector->probed_modes, head) { + if (vc4_hdmi_mode_needs_scrambling(mode)) { + drm_warn_once(drm, "The core clock cannot reach frequencies high enough to support 4k @ 60Hz."); + drm_warn_once(drm, "Please change your config.txt file to add hdmi_enable_4kp60."); + } + } + } + return ret; } @@ -959,6 +976,9 @@ static int vc4_hdmi_encoder_atomic_check(struct drm_encoder *encoder, if (pixel_rate > vc4_hdmi->variant->max_pixel_clock) return -EINVAL; + if (vc4_hdmi->disable_4kp60 && (pixel_rate > HDMI_14_MAX_TMDS_CLK)) + return -EINVAL; + vc4_state->pixel_rate = pixel_rate; return 0; @@ -978,6 +998,9 @@ vc4_hdmi_encoder_mode_valid(struct drm_encoder *encoder, if ((mode->clock * 1000) > vc4_hdmi->variant->max_pixel_clock) return MODE_CLOCK_HIGH; + if (vc4_hdmi->disable_4kp60 && vc4_hdmi_mode_needs_scrambling(mode)) + return MODE_CLOCK_HIGH; + return MODE_OK; } @@ -1993,6 +2016,14 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data) vc4_hdmi->disable_wifi_frequencies = of_property_read_bool(dev->of_node, "wifi-2.4ghz-coexistence"); + if (variant->max_pixel_clock == 600000000) { + struct vc4_dev *vc4 = to_vc4_dev(drm); + long max_rate = clk_round_rate(vc4->hvs->core_clk, 550000000); + + if (max_rate < 550000000) + vc4_hdmi->disable_4kp60 = true; + } + if (vc4_hdmi->variant->reset) vc4_hdmi->variant->reset(vc4_hdmi); diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h index 3cebd1fd00fc..3cd021136402 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.h +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h @@ -154,6 +154,14 @@ struct vc4_hdmi { */ bool disable_wifi_frequencies; + /* + * Even if HDMI0 on the RPi4 can output modes requiring a pixel + * rate higher than 297MHz, it needs some adjustments in the + * config.txt file to be able to do so and thus won't always be + * available. + */ + bool disable_4kp60; + struct cec_adapter *cec_adap; struct cec_msg cec_rx_msg; bool cec_tx_ok; -- 2.30.2 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel