Due to the voltage divider on the HPD line, the HDMI connector on imx6q-sabrelite doesn't reliably detect connected DVI monitors. This patch allows to use the RX_SENSE signals as a workaround when enabled by a boolean device tree property 'hpd-unreliable'.
Signed-off-by: Philipp Zabel p.zabel@pengutronix.de --- drivers/gpu/drm/bridge/dw-hdmi.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c index 2388a55..7ffaa44 100644 --- a/drivers/gpu/drm/bridge/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/dw-hdmi.c @@ -111,6 +111,7 @@ struct dw_hdmi { struct device *dev; struct clk *isfr_clk; struct clk *iahb_clk; + bool hpd_unreliable;
struct hdmi_data_info hdmi_data; const struct dw_hdmi_plat_data *plat_data; @@ -1413,6 +1414,8 @@ dw_hdmi_connector_detect(struct drm_connector *connector, bool force) { struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi, connector); + /* If HPD is not reliable, use RX_SENSE as fallback */ + u8 stat_mask = hdmi->hpd_unreliable ? HDMI_PHY_RX_SENSE : HDMI_PHY_HPD;
mutex_lock(&hdmi->mutex); hdmi->force = DRM_FORCE_UNSPECIFIED; @@ -1420,7 +1423,7 @@ dw_hdmi_connector_detect(struct drm_connector *connector, bool force) dw_hdmi_update_phy_mask(hdmi); mutex_unlock(&hdmi->mutex);
- if (hdmi_readb(hdmi, HDMI_PHY_STAT0) & HDMI_PHY_HPD) + if ((hdmi_readb(hdmi, HDMI_PHY_STAT0) & stat_mask) == stat_mask) return connector_status_connected;
/* free previous EDID block */ @@ -1556,7 +1559,7 @@ static irqreturn_t dw_hdmi_hardirq(int irq, void *dev_id) static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) { struct dw_hdmi *hdmi = dev_id; - u8 intr_stat, phy_int_pol, phy_pol_mask, phy_stat; + u8 intr_stat, intr_mask, phy_int_pol, phy_pol_mask, phy_stat;
intr_stat = hdmi_readb(hdmi, HDMI_IH_PHY_STAT0); phy_int_pol = hdmi_readb(hdmi, HDMI_PHY_POL0); @@ -1583,9 +1586,12 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) * other end of the link. Use this to decide whether we should * power on the phy as HPD may be toggled by the sink to merely * ask the source to re-read the EDID. + * If HPD is known to be unreliable, ignore it completely. */ - if (intr_stat & - (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD)) { + intr_mask = hdmi->hpd_unreliable ? + HDMI_IH_PHY_STAT0_RX_SENSE : + HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD; + if (intr_stat & intr_mask) { mutex_lock(&hdmi->mutex); if (!hdmi->disabled && !hdmi->force) { /* @@ -1594,14 +1600,14 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) */ if (!(phy_stat & HDMI_PHY_RX_SENSE)) hdmi->rxsense = false; - /* * Only set the software rxsense status when both * rxsense and hpd indicates we're connected. * This avoids what seems to be bad behaviour in * at least iMX6S versions of the phy. */ - if (phy_stat & HDMI_PHY_HPD) + else if ((phy_stat & HDMI_PHY_HPD) || + hdmi->hpd_unreliable) hdmi->rxsense = true;
dw_hdmi_update_power(hdmi); @@ -1617,8 +1623,7 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) }
hdmi_writeb(hdmi, intr_stat, HDMI_IH_PHY_STAT0); - hdmi_writeb(hdmi, ~(HDMI_IH_PHY_STAT0_HPD | HDMI_IH_PHY_STAT0_RX_SENSE), - HDMI_IH_MUTE_PHY_STAT0); + hdmi_writeb(hdmi, ~intr_mask, HDMI_IH_MUTE_PHY_STAT0);
return IRQ_HANDLED; } @@ -1679,6 +1684,7 @@ int dw_hdmi_bind(struct device *dev, struct device *master, struct device_node *ddc_node; struct dw_hdmi_audio_data audio; struct dw_hdmi *hdmi; + u8 intr_mask; int ret; u32 val = 1;
@@ -1770,6 +1776,8 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
initialize_hdmi_ih_mutes(hdmi);
+ hdmi->hpd_unreliable = of_property_read_bool(np, "hpd-unreliable"); + ret = devm_request_threaded_irq(dev, irq, dw_hdmi_hardirq, dw_hdmi_irq, IRQF_SHARED, dev_name(dev), hdmi); @@ -1801,8 +1809,10 @@ int dw_hdmi_bind(struct device *dev, struct device *master, goto err_iahb;
/* Unmute interrupts */ - hdmi_writeb(hdmi, ~(HDMI_IH_PHY_STAT0_HPD | HDMI_IH_PHY_STAT0_RX_SENSE), - HDMI_IH_MUTE_PHY_STAT0); + intr_mask = hdmi->hpd_unreliable ? + HDMI_IH_PHY_STAT0_RX_SENSE : + HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD; + hdmi_writeb(hdmi, ~intr_mask, HDMI_IH_MUTE_PHY_STAT0);
memset(&pdevinfo, 0, sizeof(pdevinfo)); pdevinfo.parent = dev;