On 17/01/2022 11:58, Kieran Bingham wrote:
Hi Neil,
Quoting Neil Armstrong (2022-01-17 10:08:38)
Hi again,
On 14/01/2022 15:40, Neil Armstrong wrote:
Hi,
On 14/01/2022 15:23, Biju Das wrote:
-----Original Message----- From: Neil Armstrong narmstrong@baylibre.com Sent: 14 January 2022 13:56 To: Biju Das biju.das.jz@bp.renesas.com; Fabio Estevam festevam@gmail.com Cc: daniel@ffwll.ch; Laurent.pinchart@ideasonboard.com; robert.foss@linaro.org; jonas@kwiboo.se; jernej.skrabec@gmail.com; martin.blumenstingl@googlemail.com; linux-amlogic@lists.infradead.org; linux-arm-kernel@lists.infradead.org; dri-devel@lists.freedesktop.org; linux-kernel@vger.kernel.org; linux-renesas-soc@vger.kernel.org Subject: Re: dw_hdmi is showing wrong colour after commit 7cd70656d1285b79("drm/bridge: display-connector: implement bus fmts callbacks")
Hi,
On 14/01/2022 12:08, Biju Das wrote:
Hi Neil,
> Subject: Re: dw_hdmi is showing wrong colour after commit > 7cd70656d1285b79("drm/bridge: display-connector: implement bus fmts > callbacks") > > On 14/01/2022 09:29, Biju Das wrote: >> Hi Neil, >> >> + renesas-soc >> >>> Subject: Re: dw_hdmi is showing wrong colour after commit >>> 7cd70656d1285b79("drm/bridge: display-connector: implement bus fmts >>> callbacks") >>> >>> Hi, >>> >>> On 13/01/2022 21:01, Fabio Estevam wrote: >>>> Hi Biju, >>>> >>>> On Thu, Jan 13, 2022 at 2:45 PM Biju Das >>>> biju.das.jz@bp.renesas.com >>> wrote: >>>>> >>>>> Hi All, >>>>> >>>>> RZ/G2{H, M, N} SoC has dw_hdmi IP and it was working ok(colour) >>>>> till the commit >>>>> 7cd70656d1285b79("drm/bridge: display-connector: implement bus >>>>> fmts >>> callbacks"). >>>>> >>>>> After this patch, the screen becomes greenish(may be it is >>>>> setting it >>> into YUV format??). >>>>> >>>>> By checking the code, previously it used to call get_input_fmt >>>>> callback >>> and set colour as RGB24. >>>>> >>>>> After this commit, it calls get_output_fmt_callbck and returns 3 >>>>> outputformats(YUV16, YUV24 and RGB24) And get_input_fmt callback, >>>>> I see >>> the outputformat as YUV16 instead of RGB24. >>>>> >>>>> Not sure, I am the only one seeing this issue with dw_HDMI driver. >>> >>> This patch was introduced to maintain the bridge color format >>> negotiation after using DRM_BRIDGE_ATTACH_NO_CONNECTOR, but it >>> seems it behaves incorrectly if the first bridge doesn't implement >>> the negotiation callbacks. >>> >>> Let me check the code to see how to fix that. >> >> Thanks for the information, I am happy to test the patch/fix. >> >> Cheers, >> Biju >> >>> >>>> >>>> I have tested linux-next 20220112 on a imx6q-sabresd board, which > shows: >>>> >>>> dwhdmi-imx 120000.hdmi: Detected HDMI TX controller v1.30a with >>>> HDCP (DWC HDMI 3D TX PHY) >>>> >>>> The colors are shown correctly here. >>>> >>> >>> The imx doesn't use DRM_BRIDGE_ATTACH_NO_CONNECTOR so the >>> negotiation fails and use the RGB fallback input & output format. >>> >>> Anyway thanks for testing >>> >>> Neil > > Can you test : > > ==><=============================== > diff --git a/drivers/gpu/drm/drm_bridge.c > b/drivers/gpu/drm/drm_bridge.c index c96847fc0ebc..7019acd37716 > 100644 > --- a/drivers/gpu/drm/drm_bridge.c > +++ b/drivers/gpu/drm/drm_bridge.c > @@ -955,7 +955,14 @@ drm_atomic_bridge_chain_select_bus_fmts(struct > drm_bridge *bridge, > last_bridge_state = > drm_atomic_get_new_bridge_state(crtc_state- >> state, > > last_bridge); > > - if (last_bridge->funcs->atomic_get_output_bus_fmts) { > + /* > + * Only negociate with real values if both end of the bridge
chain
> + * support negociation callbacks, otherwise you can end in a > situation > + * where the selected output format doesn't match with the > + first > bridge > + * output format. > + */ > + if (bridge->funcs->atomic_get_input_bus_fmts && > + last_bridge->funcs->atomic_get_output_bus_fmts) { > const struct drm_bridge_funcs *funcs = > last_bridge->funcs; > > /* > @@ -980,7 +987,12 @@ drm_atomic_bridge_chain_select_bus_fmts(struct > drm_bridge *bridge, > if (!out_bus_fmts) > return -ENOMEM; > > - if (conn->display_info.num_bus_formats && > + /* > + * If first bridge doesn't support negociation, use > MEDIA_BUS_FMT_FIXED > + * as a safe value for the whole bridge chain > + */ > + if (bridge->funcs->atomic_get_input_bus_fmts && > + conn->display_info.num_bus_formats && > conn->display_info.bus_formats) > out_bus_fmts[0] = conn- >> display_info.bus_formats[0]; > else > ==><=============================== > > This should exclude your situation where the first bridge doesn't > support negociation.
This fixes the issue for me here on an H3 Salvator-XS.
Could you add...
Bisected-by: Kieran Bingham kieran.bingham+renesas@ideasonboard.com Tested-by: Kieran Bingham kieran.bingham+renesas@ideasonboard.com
alongside Biju's Reported-by: tag when posting as a fix please?
Which patch did you test ?
Neil
I have tested this fix with Linux next-20220114. Still I see colour
issue.
It is still negotiating and it is calling get_output_fmt_callbck
[ 3.460155] ########dw_hdmi_bridge_atomic_get_output_bus_fmts
MEDIA_BUS_FMT_UYVY8_1X16=0#########
[ 3.460180] ########dw_hdmi_bridge_atomic_get_output_bus_fmts
MEDIA_BUS_FMT_YUV8_1X24=1#########
[ 3.460202] ########dw_hdmi_bridge_atomic_get_output_bus_fmts
MEDIA_BUS_FMT_RGB888_1X24=2#########
And In get_input_fmt callback, I See the outputformat as YUV16 instead
of RGB24.
[ 3.460319] ########dw_hdmi_bridge_atomic_get_input_bus_fmts
MEDIA_BUS_FMT_UYVY8_1X16#########
[ 3.473644] ########hdmi_video_sample
MEDIA_BUS_FMT_UYVY8_1X16#########
OK, looking at rcar-du, the dw-hdmi bridge is directly connected to the encoder.
Yep.
Let me figure that out, no sure I can find a clean solution except putting back RGB24 before YUV.
Anyway please test that:
It works now after reordering.
[ 3.493302] ########dw_hdmi_bridge_atomic_get_output_bus_fmts MEDIA_BUS_FMT_RGB888_1X24=0######### [ 3.493326] ########dw_hdmi_bridge_atomic_get_output_bus_fmts MEDIA_BUS_FMT_YUV8_1X24=1######### [ 3.493348] ########dw_hdmi_bridge_atomic_get_output_bus_fmts MEDIA_BUS_FMT_UYVY8_1X16=2#########
[ 3.493463] ########dw_hdmi_bridge_atomic_get_input_bus_fmts MEDIA_BUS_FMT_RGB888_1X24######### [ 3.506797] ########hdmi_video_sample MEDIA_BUS_FMT_RGB888_1X24#########
Is it acceptable solution to the users of dw_hdmi driver? May be it is worth to post a patch. at least it is fixing the colour issue??
Yes, it gets back to default behavior before negociation, nevertheless we need to think how to handle your use-case correctly at some point.
I'll post this as a patch ASAP so it gets applied before landing in linus master.
Neil
Regards, Biju
[...]
I'm not happy with this version since it's merely a hack which makes it work.
Can you test the following change instead, it's correctly handles your situation in a generic manner.
========================><============================= diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 54d8fdad395f..9f2e1cac0ae2 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -2551,8 +2551,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, if (!output_fmts) return NULL;
/* If dw-hdmi is the only bridge, avoid negociating with ourselves */if (list_is_singular(&bridge->encoder->bridge_chain)) {
/* If dw-hdmi is the first or only bridge, avoid negociating with ourselves */if (list_is_singular(&bridge->encoder->bridge_chain) ||list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) { *num_output_fmts = 1; output_fmts[0] = MEDIA_BUS_FMT_FIXED;@@ -2673,6 +2674,10 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge, if (!input_fmts) return NULL;
/* If dw-hdmi is the first bridge fall-back to safe output format */if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))output_fmt = MEDIA_BUS_FMT_FIXED;switch (output_fmt) { /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ case MEDIA_BUS_FMT_FIXED:========================><=============================
Thanks, Neil
Neil
Regards, Biju