lkml.org 
[lkml]   [2019]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] drm/i915/hdmi: enable resolution 3840x2160 for type 1 HDMI
On Wed, Oct 16, 2019 at 05:57:58PM +0800, Jian-Hong Pan wrote:
> Type 1 HDMI may be version 1.3 or upper, which supports higher max TMDS
> clock for higher resolutions,

Spec says "Type 1 adaptors can support DVI or HDMI up to a 165MHz TMDS clock rate."

And I've definitely seen HDMI dongles that can't deal with
eg. 1080p 12bpc @225MHz. We don't want users with black screens
out of the box, so NAK.

If you want to "overclock" your hardware you can do so by setting up
the modeline manually.

> like 3840x2160. This patch sets max TMDS
> clock according to the chip, if the adapter is type 1 HDMI.
>
> Buglink: https://bugs.freedesktop.org/show_bug.cgi?id=112018
> Fixes: b1ba124d8e95 ("drm/i915: Respect DP++ adaptor TMDS clock limit")
> Signed-off-by: Jian-Hong Pan <jian-hong@endlessm.com>
> ---
> drivers/gpu/drm/i915/display/intel_hdmi.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> index e02f0faecf02..74e4426ffcad 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> @@ -2454,6 +2454,7 @@ intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector, bool has_edid)
> {
> struct drm_i915_private *dev_priv = to_i915(connector->dev);
> struct intel_hdmi *hdmi = intel_attached_hdmi(connector);
> + struct intel_encoder *encoder = &hdmi_to_dig_port(hdmi)->base;
> enum port port = hdmi_to_dig_port(hdmi)->base.port;
> struct i2c_adapter *adapter =
> intel_gmbus_get_adapter(dev_priv, hdmi->ddc_bus);
> @@ -2488,8 +2489,16 @@ intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector, bool has_edid)
> return;
>
> hdmi->dp_dual_mode.type = type;
> - hdmi->dp_dual_mode.max_tmds_clock =
> - drm_dp_dual_mode_max_tmds_clock(type, adapter);
> + /* Type 1 HDMI may be version 1.3 or upper, which supports higher max
> + * TMDS clock for higher resolutions, like 3840x2160. So, set it
> + * according to the chip, if the adapter is type 1 HDMI.
> + */
> + if (type == DRM_DP_DUAL_MODE_TYPE1_HDMI)
> + hdmi->dp_dual_mode.max_tmds_clock =
> + intel_hdmi_source_max_tmds_clock(encoder);
> + else
> + hdmi->dp_dual_mode.max_tmds_clock =
> + drm_dp_dual_mode_max_tmds_clock(type, adapter);
>
> DRM_DEBUG_KMS("DP dual mode adaptor (%s) detected (max TMDS clock: %d kHz)\n",
> drm_dp_get_dual_mode_type_name(type),
> --
> 2.23.0

--
Ville Syrjälä
Intel

\
 
 \ /
  Last update: 2019-10-16 12:34    [W:0.051 / U:5.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site