Unverified Commit da09daf8 authored by Lucas Stach's avatar Lucas Stach Committed by Robert Foss
Browse files

drm: bridge: dw_hdmi: only trigger hotplug event on link change 



There are two events that signal a real change of the link state: HPD going
high means the sink is newly connected or wants the source to re-read the
EDID, RX sense going low is a indication that the link has been disconnected.

Ignore the other two events that also trigger interrupts, but don't need
immediate attention: HPD going low does not necessarily mean the link has
been lost and should not trigger a immediate read of the status. RX sense
going high also does not require a detect cycle, as HPD going high is the
right point in time to read the EDID.

Signed-off-by: default avatarLucas Stach <l.stach@pengutronix.de>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> (v1)
Reviewed-by: default avatarRobert Foss <robert.foss@linaro.org>
Signed-off-by: default avatarRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220826185733.3213248-1-l.stach@pengutronix.de
parent 81dae1f3

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

+8 −5
Original line number Diff line number Diff line
@@ -3096,6 +3096,7 @@ 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;

	enum drm_connector_status status = connector_status_unknown;



	intr_stat = hdmi_readb(hdmi, HDMI_IH_PHY_STAT0);

	phy_int_pol = hdmi_readb(hdmi, HDMI_PHY_POL0);
@@ -3134,13 +3135,15 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) 
			cec_notifier_phys_addr_invalidate(hdmi->cec_notifier);

			mutex_unlock(&hdmi->cec_notifier_mutex);

		}

	}



	if (intr_stat & HDMI_IH_PHY_STAT0_HPD) {

		enum drm_connector_status status = phy_int_pol & HDMI_PHY_HPD

						 ? connector_status_connected

						 : connector_status_disconnected;

		if (phy_stat & HDMI_PHY_HPD)

			status = connector_status_connected;



		if (!(phy_stat & (HDMI_PHY_HPD | HDMI_PHY_RX_SENSE)))

			status = connector_status_disconnected;

	}



	if (status != connector_status_unknown) {

		dev_dbg(hdmi->dev, "EVENT=%s\n",

			status == connector_status_connected ?

			"plugin" : "plugout");