Re: [PATCH] drm/bridge: dw-hdmi-qp: Return -EOPNOTSUPP in HDMI audio functions

From: Cristian Ciocaltea

Date: Sat Oct 17 2026 - 13:40:38 EST


Hi,

On 5/19/26 9:00 PM, Detlev Casanova wrote:
> -EOPNOTSUPP is not logged as an error by the ASoC subsystem, but -ENODEV
> is.
> It also better represents the situation: The operation is currently not
> supported (because clocks are not enabled and tmds_char_rate is
> unavailable), but the hardware is present.
>
> Using -EOPNOTSUPP in the audio_prepare callback removes possible repeated
> warning log lines when HDMI is not connected.
>
> Returning -EOPNOTSUPP in the audio_enable callback is also needed as it
> avoids logging 0-valued ELD errors.
>
> When tmds_char_rate is available, the clocks are enabled and the
> functions will keep returning 0 as before.
>
> Signed-off-by: Detlev Casanova <detlev.casanova@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
> index d649a1cf07f5..270c8c47d853 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
> @@ -469,8 +469,10 @@ static int dw_hdmi_qp_audio_enable(struct drm_bridge *bridge,
> {
> struct dw_hdmi_qp *hdmi = dw_hdmi_qp_from_bridge(bridge);
>
> - if (hdmi->tmds_char_rate)
> - dw_hdmi_qp_mod(hdmi, 0, AVP_DATAPATH_PACKET_AUDIO_SWDISABLE, GLOBAL_SWDISABLE);
> + if (!hdmi->tmds_char_rate)
> + return -EOPNOTSUPP;
> +
> + dw_hdmi_qp_mod(hdmi, 0, AVP_DATAPATH_PACKET_AUDIO_SWDISABLE, GLOBAL_SWDISABLE);
>
> return 0;
> }
> @@ -484,7 +486,7 @@ static int dw_hdmi_qp_audio_prepare(struct drm_bridge *bridge,
> bool ref2stream = false;
>
> if (!hdmi->tmds_char_rate)
> - return -ENODEV;
> + return -EOPNOTSUPP;
>
> if (fmt->bit_clk_provider | fmt->frame_clk_provider) {
> dev_err(hdmi->dev, "unsupported clock settings\n");
>
This LGTM, hence:

Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>

Sadly, the patch was submitted before MAINTAINERS was updated to track
dw-hdmi-qp under Rockchip DRM, so it missed some email recipients..

+ Heiko Stübner <heiko@xxxxxxxxx>
+ linux-rockchip@xxxxxxxxxxxxxxxxxxx

Thanks to Sebastian for noticing this fell through the cracks.
It still applies cleanly on top of latest drm-misc-next.

Heiko, can we get it merged, please?

Regards,
Cristian