Re: [PATCH 0/8] drm/meson: Add support for HDMI2.0 4k60

From: Andrzej Hajda
Date: Thu Jan 31 2019 - 09:13:12 EST


On 31.01.2019 14:25, Neil Armstrong wrote:
> Hi Andrzej, Laurent,
>
> On 15/01/2019 13:33, Neil Armstrong wrote:
>> This patchset aims to add support for the following HDMI2.0 4k60 modes:
>> - 594Mhz TMDS frequency needing TMDS Scramling and 1/40 rate for RGB/YUV4:4:4
>> - 297MHz TMDS frequency with YUV4:2:0 encoding
>>
>> The first mode uses the SCDC helpers introduced by intel to :
>> - discover where the monitor support SCDC
>> - setup the SCDC parameters
>> This is implemented in the dw-hdmi bridge driver by handling scrambling
>> support during the bridge setup and by exporting an helper for the PHY
>> setup to setup the SCDC configuration for the 1/40 TMDS rate.
>> This code will only be active if the encoder support a TMDS rate > 340MHz.
>>
>> This patch could eventually break support on different SoC when connected
>> on a 4k60 monitor with SCDC :
>> - i.MX correctly discards pixel clocks > 216MHz
>> - R-CAR discards discards pixel clocks > 297MHz since [1]
>> - Rockchip discards invalid pixel clocks not in the rockchip_mpll_cfg table
>> - sun8i correctly discards pixel clocks > 297MHz on a83t
>> - sun8i discards discards pixel clocks > 594Mhz on h6, which is already broken
>>
>> First patch should fix support for Allwinner H6.
>>
>> The second mode is implemented by added the missing 4:2:0 bypass handling
>> in the dw-hdmi bridge driver and adding a "mtmdsclock" separating the
>> pixel clock from the tmds clock in the mode setup phase.
>> We also enable support for these modes in the connector only if the platform
>> glue code explicits the support.
> Do you think patches 1-4 could be applied ?


For me they are OK.

Should I take them via drm-misc?


>
> Then we could focus on how we manage the bus format between the encoder
> and the bridge ?
>
> Especially patch 5 linked to patch 7.
>
> Will one of you be at FOSDEM 2019 ? we could chat about this.


Nope.


Regards

Andrzej


>
> Following subjects on the table will be :
> - HDR metadata transmission aligned with the last patchset sent by intel-gfx
> - Colorspace connector property aligned with the last patchset sent by intel-gfx
> - HDCP 1.4 and 2.2 handling
>
> Neil
>
>> Only the meson DRM dw_hdmi glue allows ycbcr420 modes, so no breakage
>> is expected here.
>>
>> The remaining patches adds support for :
>> - 1/40 TMDS rate aka DIV40 in the dw-hdmi meson PHY setup
>> - 4:2:0 output and clock setup
>>
>> The dw-hdmi support re-uses the support done by Rockchip engineers on the
>> Linux 4.4 BSP kernel.
>>
>> These modes has been validated using a MuxLab HDMI Signal Analyser in
>> addition to different UHD TVs supporting full 4k60 or the 4:2:0 variant.
>>
>> Changes since RFC v2 at [3]:
>> - Collected tested-by and reviewed-by tags
>> - Changed if condition in "add HDMI div40 TMDS mode"
>> - Updated "Add YUV420 output support" with the same if condition
>>
>> Changes since RFC v1 at [2]:
>> - Fix all comments from Laurent :
>> - Add define for HDMI 1.4 max tmds clock and SCDC supported version
>> - Call dw_hdmi_set_high_tmds_clock_ratio() in dw_hdmi_phy_enable_powerdown()
>> to unbreak Allwinner H6
>> - Pass in_t(u8, bytes, SCDC_MIN_SOURCE_VERSION) as SCDC version
>> - Finally add comments for SCDC and Scrambling process
>>
>> [1] https://patchwork.freedesktop.org/patch/263616/
>> [2] https://patchwork.freedesktop.org/series/52950/#rev1
>> [3] https://patchwork.freedesktop.org/series/52950/#rev2
>>
>> Neil Armstrong (7):
>> drm/bridge: dw-hdmi: Add SCDC and TMDS Scrambling support
>> drm/meson: add HDMI div40 TMDS mode
>> drm/meson: add support for HDMI2.0 2160p modes
>> drm/bridge: dw-hdmi: add support for YUV420 output
>> drm/bridge: dw-hdmi: allow ycbcr420 modes for >= 0x200a
>> drm/meson: Add YUV420 output support
>> drm/meson: Output in YUV444 if sink supports it
>>
>> Zheng Yang (1):
>> drm/bridge: dw-hdmi: support dynamically get input/out color info
>>
>> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 182 +++++++++++++++++++---
>> drivers/gpu/drm/bridge/synopsys/dw-hdmi.h | 1 +
>> drivers/gpu/drm/meson/meson_dw_hdmi.c | 128 ++++++++++++---
>> drivers/gpu/drm/meson/meson_vclk.c | 93 ++++++++---
>> drivers/gpu/drm/meson/meson_vclk.h | 7 +-
>> drivers/gpu/drm/meson/meson_venc.c | 8 +-
>> drivers/gpu/drm/meson/meson_venc.h | 11 ++
>> drivers/gpu/drm/meson/meson_venc_cvbs.c | 3 +-
>> include/drm/bridge/dw_hdmi.h | 7 +
>> 9 files changed, 374 insertions(+), 66 deletions(-)
>>
>
>