drm/bridge: dw-hdmi: handle ELD when DRM_BRIDGE_ATTACH_NO_CONNECTOR

[ Upstream commit 3f2532d65a571ca02258b547b5b68ab2e9406fdb ]

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 (or 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@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
[narmstrong: fixed typo in commit log]
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211029135947.3022875-1-narmstrong@baylibre.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

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 d0db1ac..7d2ed0e 100644 (file)
--- 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 cb07dc0..f72d272 100644 (file)
--- 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 feb04f1..f50b47a 100644 (file)
--- 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 f08d0fd..e1211a5 100644 (file)
--- 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);
@@ -3431,7 +3439,7 @@ 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;
 
@@ -3444,7 +3452,7 @@ 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;