linux-kernel - Re: [PATCH] drm/radeon: Solve the problem of the audio options not disappearing promptly after unplugging the HDMI audio.

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Message-ID: <CADnq5_PCGv7a4azG+mhv+=Jmp74-O73iUnZctLkNYKabRGcwMg@mail.gmail.com>
Date: Wed, 24 Sep 2025 13:58:59 -0400
From: Alex Deucher <alexdeucher@...il.com>
To: 2564278112@...com
Cc: alexander.deucher@....com, christian.koenig@....com, airlied@...il.com, 
	simona@...ll.ch, amd-gfx@...ts.freedesktop.org, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
	Wang Jiang <jiangwang@...inos.cn>
Subject: Re: [PATCH] drm/radeon: Solve the problem of the audio options not
 disappearing promptly after unplugging the HDMI audio.

On Wed, Sep 24, 2025 at 7:44 AM <2564278112@...com> wrote:
>
> From: Wang Jiang <jiangwang@...inos.cn>
>
> The audio detection process in the Radeon driver is as follows:
> radeon_dvi_detect/radeon_dp_detect -> radeon_audio_detect -> radeon_audio_enable -> radeon_audio_component_notify -> radeon_audio_component_get_eld
> When HDMI is unplugged, radeon_dvi_detect is triggered.
> At this point, radeon_audio_detect is triggered before radeon_dvi_detect has finished (which also means the new state of the connector has not been reported).
> In this scenario, radeon_audio_detect can detect that the connector is disconnected (because the parameter is passed down),
>  but it is very likely that the audio callback function radeon_audio_component_get_eld cannot detect the disconnection of the connector.
> As a result, when the audio component (radeon_audio_component_get_eld) performs detection, the connector's state is not shown as disconnected,
> and connector->eld is not zero, causing the audio component to think the audio driver is still working.
> I have added a new member (enable_mask) to the audio structure to record the audio enable status.
> Only when radeon_audio_component_get_eld detects that enable_mask is not zero will it continue to work.
> There might be other solutions, such as placing radeon_audio_detect/radeon_audio_component_notify after the completion of radeon_XX_detect.
> However, I found that this would require significant changes (or perhaps it's just my limited coding skills?).

This still looks like a race.  I think the get_eld() callback can get
called whenever.  The proper fix is probably to hold the
connector->eld_mutex in radeon_audio_detect().

Alex

>
> Signed-off-by: Wang Jiang <jiangwang@...inos.cn>
> ---
>  drivers/gpu/drm/radeon/radeon.h       | 1 +
>  drivers/gpu/drm/radeon/radeon_audio.c | 5 +++++
>  2 files changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> index 63c47585afbc..2d0a411e3ed6 100644
> --- a/drivers/gpu/drm/radeon/radeon.h
> +++ b/drivers/gpu/drm/radeon/radeon.h
> @@ -1745,6 +1745,7 @@ struct r600_audio_pin {
>         u32                     offset;
>         bool                    connected;
>         u32                     id;
> +       u8                      enable_mask;
>  };
>
>  struct r600_audio {
> diff --git a/drivers/gpu/drm/radeon/radeon_audio.c b/drivers/gpu/drm/radeon/radeon_audio.c
> index 8d64ba18572e..a0717895cc8a 100644
> --- a/drivers/gpu/drm/radeon/radeon_audio.c
> +++ b/drivers/gpu/drm/radeon/radeon_audio.c
> @@ -212,6 +212,7 @@ static void radeon_audio_enable(struct radeon_device *rdev,
>         if (rdev->audio.funcs->enable)
>                 rdev->audio.funcs->enable(rdev, pin, enable_mask);
>
> +       rdev->audio.pin[pin->id].enable_mask = enable_mask;
>         radeon_audio_component_notify(rdev, pin->id);
>  }
>
> @@ -274,6 +275,7 @@ int radeon_audio_init(struct radeon_device *rdev)
>                 rdev->audio.pin[i].connected = false;
>                 rdev->audio.pin[i].offset = pin_offsets[i];
>                 rdev->audio.pin[i].id = i;
> +               rdev->audio.pin[i].enable_mask = 0;
>         }
>
>         radeon_audio_interface_init(rdev);
> @@ -760,6 +762,9 @@ static int radeon_audio_component_get_eld(struct device *kdev, int port,
>         if (!rdev->audio.enabled || !rdev->mode_info.mode_config_initialized)
>                 return 0;
>
> +       if (rdev->audio.pin[port].enable_mask == 0)
> +               return 0;
> +
>         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
>                 const struct drm_connector_helper_funcs *connector_funcs =
>                                 connector->helper_private;
> --
> 2.25.1
>