[why]
Current policy assumes virtual DPCD peer device as
an individual MST branch device with 1 input and 1 output.
However this is only true for virtual DP-to-DP peer device.
In general there are three types of virtual DP peer devices.
1. Sink peer device with virtual DPCD.
2. Virtual DP-to-DP Peer device with virtual DPCD.
3. Virtual DP-to-HDMI Protocol Converter Peer Device with
Virtual DPCD.
So we should break the assumption and handle all three types.
[how]
DP-to-DP peer device will have virtual DPCD cap upstream.
Sink peer device will have virtual DPCD on the logical port.
Dp to HDMI protocol converter peer device will have virtual DPCD
on its converter port.
For DSC capable Synaptics non VGA port we workaround by enumerating
a virutal DPCD peer device on its upstream
even if it doesn't have one.
Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[why]
A few of the new DSC DPCD caps were introduced by a DP 1.4a SCR in order
to give DSC branch decoders a chance to expose their maximum throughput
and maximum line width limitations.
Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[why]
DSC target bpp precision is a decoder DPCD and an AMD encoder capability.
It must be taken into account when calculating target bitrate.
[how]
Add a DC DSC function that does this calculation.
Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[why]
The current policy will always enable DSC to 12 bpp
regardless of if the current bandwidth is enough for MST displays.
This logic is not optimal because user will get lower quality output
if DSC compression is enabled.
This change to is to implement a DSC MST bandwidth fair share
algorithm so we will dynamically decide if DSC is needed and what
quality (target bpp) is needed to fairly destribute the MST bandwidth
in one MST topology. This will allow user to see the most optimal
image quality with the given bandwidth.
[how]
We will start with lowest bandwidth possible and run a
Max-Min fairness algorithm to fairly distribute the available
bandwidth. If there is still remaining bandwidth, we will try to fit
the timing without DSC compression.
Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[why]
Clean up some dsc legacy functions that are
no longer needed.
[how]
remove two dsc functions in dc_dsc, use dc_bandwidth_in_kbps_from_timing
instead of calc_required_bandwidth_for_timing.
Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Nikola Cornij <Nikola.Cornij@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
