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References: <20220127081237.13903-1-Tsung-Hua.Lin@amd.com> <20220330024643.162230-1-tsung-hua.lin@amd.com>
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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Tue, 29 Mar 2022 23:01:52 -0400
Message-ID: <CADnq5_O6S+7Kk34fGCjqmmJAf5JtZP35+MBpCDQnH5Sh6ZosFA@mail.gmail.com>
Subject: Re: [PATCH v2] drm/amdgpu: fix that issue that the number of the crtc
 of the 3250c is not correct
To:     Ryan Lin <tsung-hua.lin@amd.com>
Cc:     "David (ChunMing) Zhou" <David1.Zhou@amd.com>,
        Drew Davenport <ddavenport@chromium.org>,
        Leo Li <sunpeng.li@amd.com>, leon.li@amd.com,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
        LKML <linux-kernel@vger.kernel.org>,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        David Airlie <airlied@linux.ie>,
        Sean Paul <seanpaul@chromium.org>,
        Louis Li <ching-shih.li@amd.corp-partner.google.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>,
        Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?Q?St=C3=A9phane_Marchesin?= <marcheu@chromium.org>,
        Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>,
        Harry Wentland <harry.wentland@amd.com>,
        Mark Yacoub <markyacoub@google.com>
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On Tue, Mar 29, 2022 at 10:57 PM Ryan Lin <tsung-hua.lin@amd.com> wrote:
>
> [Why]
> External displays take priority over internal display when there are fewer
> display controllers than displays.
>
> [How]
> The root cause is because of that number of the crtc is not correct.
> The number of the crtc on the 3250c is 3, but on the 3500c is 4.
> On the source code, we can see that number of the crtc has been fixed at 4.
> Needs to set the num_crtc to 3 for 3250c platform.
>
> v2:
>    - remove unnecessary comments and Id
>
> Signed-off-by: Ryan Lin <tsung-hua.lin@amd.com>

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

>
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 40c91b448f7da..455a2c45e8cda 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -2738,9 +2738,15 @@ static int dm_early_init(void *handle)
>                 break;
>  #if defined(CONFIG_DRM_AMD_DC_DCN1_0)
>         case CHIP_RAVEN:
> -               adev->mode_info.num_crtc = 4;
> -               adev->mode_info.num_hpd = 4;
> -               adev->mode_info.num_dig = 4;
> +               if (adev->rev_id >= 8) {
> +                       adev->mode_info.num_crtc = 3;
> +                       adev->mode_info.num_hpd = 3;
> +                       adev->mode_info.num_dig = 3;
> +               } else {
> +                       adev->mode_info.num_crtc = 4;
> +                       adev->mode_info.num_hpd = 4;
> +                       adev->mode_info.num_dig = 4;
> +               }
>                 break;
>  #endif
>  #if defined(CONFIG_DRM_AMD_DC_DCN2_0)
> --
> 2.25.1
>