| Message ID | 20240908132823.3308029-2-jonas@kwiboo.se (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: bridge: dw_hdmi: Misc enable/disable, CEC and EDID cleanup | expand |
On 08/09/2024 15:28, Jonas Karlman wrote: > The scrambler feature can be left enabled when hotplugging from a sink > and mode that require scrambling to a sink that does not support SCDC or > scrambling. > > Typically a blank screen or 'no signal' message can be observed after > using a HDMI 2.0 4K@60Hz mode and then hotplugging to a sink that only > support HDMI 1.4. > > Fix this by disabling the scrambler feature when SCDC is not supported. > > Fixes: 264fce6cc2c1 ("drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support") > Reported-by: Christopher Obbard <chris.obbard@collabora.com> > Signed-off-by: Jonas Karlman <jonas@kwiboo.se> > --- > v2: New patch > --- > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > index 0031f3c54882..9e7f86a0bf5c 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > @@ -2117,6 +2117,8 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi, > HDMI_MC_SWRSTZ); > drm_scdc_set_scrambling(hdmi->curr_conn, 0); > } > + } else if (hdmi->version >= 0x200a) { > + hdmi_writeb(hdmi, 0, HDMI_FC_SCRAMBLER_CTRL); > } > > /* Set up horizontal active pixel width */ Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 0031f3c54882..9e7f86a0bf5c 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2117,6 +2117,8 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi, HDMI_MC_SWRSTZ); drm_scdc_set_scrambling(hdmi->curr_conn, 0); } + } else if (hdmi->version >= 0x200a) { + hdmi_writeb(hdmi, 0, HDMI_FC_SCRAMBLER_CTRL); } /* Set up horizontal active pixel width */
The scrambler feature can be left enabled when hotplugging from a sink and mode that require scrambling to a sink that does not support SCDC or scrambling. Typically a blank screen or 'no signal' message can be observed after using a HDMI 2.0 4K@60Hz mode and then hotplugging to a sink that only support HDMI 1.4. Fix this by disabling the scrambler feature when SCDC is not supported. Fixes: 264fce6cc2c1 ("drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support") Reported-by: Christopher Obbard <chris.obbard@collabora.com> Signed-off-by: Jonas Karlman <jonas@kwiboo.se> --- v2: New patch --- drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 2 ++ 1 file changed, 2 insertions(+)