linux-kernel - RE: dw_hdmi is showing wrong colour after commit 7cd70656d1285b79("drm/bridge: display-connector: implement bus fmts callbacks")

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <OS0PR01MB592224EC8F50F41B7FF1DEE286549@OS0PR01MB5922.jpnprd01.prod.outlook.com>
Date:   Fri, 14 Jan 2022 08:29:28 +0000
From:   Biju Das <biju.das.jz@...renesas.com>
To:     Neil Armstrong <narmstrong@...libre.com>,
        Fabio Estevam <festevam@...il.com>
CC:     "daniel@...ll.ch" <daniel@...ll.ch>,
        "Laurent.pinchart@...asonboard.com" 
        <Laurent.pinchart@...asonboard.com>,
        "robert.foss@...aro.org" <robert.foss@...aro.org>,
        "jonas@...boo.se" <jonas@...boo.se>,
        "jernej.skrabec@...il.com" <jernej.skrabec@...il.com>,
        "martin.blumenstingl@...glemail.com" 
        <martin.blumenstingl@...glemail.com>,
        "linux-amlogic@...ts.infradead.org" 
        <linux-amlogic@...ts.infradead.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-renesas-soc@...r.kernel.org" 
        <linux-renesas-soc@...r.kernel.org>
Subject: RE: dw_hdmi is showing wrong colour after commit
 7cd70656d1285b79("drm/bridge: display-connector: implement bus fmts
 callbacks")

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@...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