diff options
| author | Chris Morgan <macromorgan@hotmail.com> | 2025-11-19 16:55:25 -0600 |
|---|---|---|
| committer | Heiko Stuebner <heiko@sntech.de> | 2026-01-09 20:23:43 +0100 |
| commit | bafb6863dd8cea94e7dc2f90979b30292e8ea31c (patch) | |
| tree | 0c83b0589595f56f203b7e294e798ea733c89db8 | |
| parent | db04f0d47dd1f18cf506a7dfa00035901be328a1 (diff) | |
drm/bridge: dw-hdmi-qp: Add support for missing HPD
Add support for the dw-hdmi-qp driver to handle devices with missing
HPD pins.
Since in this situation we are now polling for the EDID data via i2c
change the error message to a rate limited debug message when we are
unable to complete an i2c read, as a disconnected device would
otherwise fill dmesg with i2c read errors.
Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20251119225526.70588-3-macroalpha82@gmail.com
| -rw-r--r-- | drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c index fe4c026280f0..0c7ad06aaca4 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c @@ -165,6 +165,7 @@ struct dw_hdmi_qp { struct regmap *regm; unsigned long tmds_char_rate; + bool no_hpd; }; static void dw_hdmi_qp_write(struct dw_hdmi_qp *hdmi, unsigned int val, @@ -555,14 +556,22 @@ static int dw_hdmi_qp_i2c_read(struct dw_hdmi_qp *hdmi, stat = wait_for_completion_timeout(&i2c->cmp, HZ / 10); if (!stat) { - dev_err(hdmi->dev, "i2c read timed out\n"); + if (hdmi->no_hpd) + dev_dbg_ratelimited(hdmi->dev, + "i2c read timed out\n"); + else + dev_err(hdmi->dev, "i2c read timed out\n"); dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0); return -EAGAIN; } /* Check for error condition on the bus */ if (i2c->stat & I2CM_NACK_RCVD_IRQ) { - dev_err(hdmi->dev, "i2c read error\n"); + if (hdmi->no_hpd) + dev_dbg_ratelimited(hdmi->dev, + "i2c read error\n"); + else + dev_err(hdmi->dev, "i2c read error\n"); dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0); return -EIO; } @@ -900,6 +909,15 @@ static enum drm_connector_status dw_hdmi_qp_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector) { struct dw_hdmi_qp *hdmi = bridge->driver_private; + const struct drm_edid *drm_edid; + + if (hdmi->no_hpd) { + drm_edid = drm_edid_read_ddc(connector, bridge->ddc); + if (drm_edid) + return connector_status_connected; + else + return connector_status_disconnected; + } return hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data); } @@ -925,6 +943,11 @@ dw_hdmi_qp_bridge_tmds_char_rate_valid(const struct drm_bridge *bridge, { struct dw_hdmi_qp *hdmi = bridge->driver_private; + /* + * TODO: when hdmi->no_hpd is 1 we must not support modes that + * require scrambling, including every mode with a clock above + * HDMI14_MAX_TMDSCLK. + */ if (rate > HDMI14_MAX_TMDSCLK) { dev_dbg(hdmi->dev, "Unsupported TMDS char rate: %lld\n", rate); return MODE_CLOCK_HIGH; @@ -1277,12 +1300,15 @@ struct dw_hdmi_qp *dw_hdmi_qp_bind(struct platform_device *pdev, if (ret) return ERR_PTR(ret); + hdmi->no_hpd = device_property_read_bool(dev, "no-hpd"); + hdmi->bridge.driver_private = hdmi; hdmi->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HDMI | - DRM_BRIDGE_OP_HDMI_AUDIO | - DRM_BRIDGE_OP_HPD; + DRM_BRIDGE_OP_HDMI_AUDIO; + if (!hdmi->no_hpd) + hdmi->bridge.ops |= DRM_BRIDGE_OP_HPD; hdmi->bridge.of_node = pdev->dev.of_node; hdmi->bridge.type = DRM_MODE_CONNECTOR_HDMIA; hdmi->bridge.vendor = "Synopsys"; |