phy: qcom-qmp-combo: fix drm bridge registration

Due to a long-standing issue in driver core, drivers may not probe defer
after having registered child devices to avoid triggering a probe
deferral loop (see fbc35b4 ("Add documentation on meaning of
-EPROBE_DEFER")).

This could potentially also trigger a bug in the DRM bridge
implementation which does not expect bridges to go away even if device
links may avoid triggering this (when enabled).

Move registration of the DRM aux bridge to after looking up clocks and
other resources.

Note that PHY creation can in theory also trigger a probe deferral when
a 'phy' supply is used. This does not seem to affect the QMP PHY driver
but the PHY subsystem should be reworked to address this (i.e. by
separating initialisation and registration of the PHY).

Fixes: 3592191 ("phy: qcom: qmp-combo: switch to DRM_AUX_BRIDGE")
Fixes: 1904c3f ("phy: qcom-qmp-combo: Introduce drm_bridge")
Cc: [email protected]      # 6.5
Cc: Bjorn Andersson <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Reviewed-by: Neil Armstrong <[email protected]>
Reviewed-by: Bjorn Andersson <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Acked-by: Vinod Koul <[email protected]>
Acked-by: Neil Armstrong <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: jhovold

drivers/phy/qualcomm/phy-qcom-qmp-combo.c

@@ -3566,10 +3566,6 @@ static int qmp_combo_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	ret = drm_aux_bridge_register(dev);
-	if (ret)
-		return ret;
-
 	/* Check for legacy binding with child nodes. */
 	usb_np = of_get_child_by_name(dev->of_node, "usb3-phy");
 	if (usb_np) {
@@ -3589,6 +3585,10 @@ static int qmp_combo_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_node_put;
 
+	ret = drm_aux_bridge_register(dev);
+	if (ret)
+		goto err_node_put;
+
 	pm_runtime_set_active(dev);
 	ret = devm_pm_runtime_enable(dev);
 	if (ret)