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drm/vc4: hdmi: Check and warn if we can't reach 4kp60 frequencies

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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@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210507150515.257424-10-maxime@cerno.tech
This commit is contained in:
Maxime Ripard 2021-05-07 17:05:12 +02:00
parent 7d9061e097
commit 86e3a65fdb
No known key found for this signature in database
GPG key ID: E3EF0D6F671851C5
2 changed files with 39 additions and 0 deletions
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31
drivers/gpu/drm/vc4/vc4_hdmi.c
View file

@ -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;
}
@ -1015,6 +1032,9 @@ 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;
@ -1034,6 +1054,9 @@ 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;
}
@ -2049,6 +2072,14 @@ 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);

8
drivers/gpu/drm/vc4/vc4_hdmi.h
View file

@ -157,6 +157,14 @@ 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;