Hi drm/bridge maintainers,
On 29/10/2021 15:59, Neil Armstrong wrote:
> The current ELD handling takes the internal connector ELD buffer and
> shares it to the I2S and AHB sub-driver.
>
> But with DRM_BRIDGE_ATTACH_NO_CONNECTOR, the connector is created
> elsewhere (not not), and an eventual connector is known only
> if the bridge chain up to a connector is enabled.
>
> The current dw-hdmi code gets the current connector from
> atomic_enable() so use the already stored connector pointer and
> replace the buffer pointer with a callback returning the current
> connector ELD buffer.
>
> Since a connector is not always available, either pass an empty
> ELD to the alsa HDMI driver or don't call snd_pcm_hw_constraint_eld()
> in AHB driver.
>
> Reported-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c | 10 +++++++---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h | 4 ++--
> drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c | 9 ++++++++-
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 12 ++++++++++--
> 4 files changed, 27 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c
> index d0db1acf11d7..7d2ed0ed2fe2 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c
> @@ -320,13 +320,17 @@ static int dw_hdmi_open(struct snd_pcm_substream *substream)
> struct snd_pcm_runtime *runtime = substream->runtime;
> struct snd_dw_hdmi *dw = substream->private_data;
> void __iomem *base = dw->data.base;
> + u8 *eld;
> int ret;
>
> runtime->hw = dw_hdmi_hw;
>
> - ret = snd_pcm_hw_constraint_eld(runtime, dw->data.eld);
> - if (ret < 0)
> - return ret;
> + eld = dw->data.get_eld(dw->data.hdmi);
> + if (eld) {
> + ret = snd_pcm_hw_constraint_eld(runtime, eld);
> + if (ret < 0)
> + return ret;
> + }
>
> ret = snd_pcm_limit_hw_rates(runtime);
> if (ret < 0)
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> index cb07dc0da5a7..f72d27208ebe 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> @@ -9,15 +9,15 @@ struct dw_hdmi_audio_data {
> void __iomem *base;
> int irq;
> struct dw_hdmi *hdmi;
> - u8 *eld;
> + u8 *(*get_eld)(struct dw_hdmi *hdmi);
> };
>
> struct dw_hdmi_i2s_audio_data {
> struct dw_hdmi *hdmi;
> - u8 *eld;
>
> void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
> u8 (*read)(struct dw_hdmi *hdmi, int offset);
> + u8 *(*get_eld)(struct dw_hdmi *hdmi);
> };
>
> #endif
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> index feb04f127b55..f50b47ac11a8 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> @@ -135,8 +135,15 @@ static int dw_hdmi_i2s_get_eld(struct device *dev, void *data, uint8_t *buf,
> size_t len)
> {
> struct dw_hdmi_i2s_audio_data *audio = data;
> + u8 *eld;
> +
> + eld = audio->get_eld(audio->hdmi);
> + if (eld)
> + memcpy(buf, eld, min_t(size_t, MAX_ELD_BYTES, len));
> + else
> + /* Pass en empty ELD if connector not available */
> + memset(buf, 0, len);
>
> - memcpy(buf, audio->eld, min_t(size_t, MAX_ELD_BYTES, len));
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 62ae63565d3a..54d8fdad395f 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -757,6 +757,14 @@ static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi, bool enable)
> hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
> }
>
> +static u8 *hdmi_audio_get_eld(struct dw_hdmi *hdmi)
> +{
> + if (!hdmi->curr_conn)
> + return NULL;
> +
> + return hdmi->curr_conn->eld;
> +}
> +
> static void dw_hdmi_ahb_audio_enable(struct dw_hdmi *hdmi)
> {
> hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
> @@ -3432,7 +3440,7 @@ struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
> audio.base = hdmi->regs;
> audio.irq = irq;
> audio.hdmi = hdmi;
> - audio.eld = hdmi->connector.eld;
> + audio.get_eld = hdmi_audio_get_eld;
> hdmi->enable_audio = dw_hdmi_ahb_audio_enable;
> hdmi->disable_audio = dw_hdmi_ahb_audio_disable;
>
> @@ -3445,7 +3453,7 @@ struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
> struct dw_hdmi_i2s_audio_data audio;
>
> audio.hdmi = hdmi;
> - audio.eld = hdmi->connector.eld;
> + audio.get_eld = hdmi_audio_get_eld;
> audio.write = hdmi_writeb;
> audio.read = hdmi_readb;
> hdmi->enable_audio = dw_hdmi_i2s_audio_enable;
>
Is there someone who can have a look at this ?
I won't push https://lore.kernel.org/r/20211020123947.2585572-1-narmstrong@xxxxxxxxxxxx until this is fixed
because with DRM_BRIDGE_ATTACH_NO_CONNECTOR we loose the ELD on the HDMI sound card,
Neil
