From d2d7b8e88023b75320662c2305d61779ff060950 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sat, 17 Feb 2024 16:02:27 +0100 Subject: [PATCH 1/2] 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 fbc35b45f9f6 ("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: 35921910bbd0 ("phy: qcom: qmp-combo: switch to DRM_AUX_BRIDGE") Fixes: 1904c3f578dc ("phy: qcom-qmp-combo: Introduce drm_bridge") Cc: stable@vger.kernel.org # 6.5 Cc: Bjorn Andersson Cc: Dmitry Baryshkov Signed-off-by: Johan Hovold Reviewed-by: Neil Armstrong Reviewed-by: Bjorn Andersson Reviewed-by: Dmitry Baryshkov Acked-by: Vinod Koul Acked-by: Neil Armstrong Link: https://lore.kernel.org/r/20240217150228.5788-6-johan+linaro@kernel.org Signed-off-by: Vinod Koul --- drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c index 1ad10110dd25..e19d6a084f10 100644 --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c +++ b/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) From 47b412c1ea77112f1148b4edd71700a388c7c80f Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sat, 17 Feb 2024 16:02:28 +0100 Subject: [PATCH 2/2] phy: qcom-qmp-combo: fix type-c switch 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 fbc35b45f9f6 ("Add documentation on meaning of -EPROBE_DEFER")). Move registration of the typec switch 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: 2851117f8f42 ("phy: qcom-qmp-combo: Introduce orientation switching") Cc: stable@vger.kernel.org # 6.5 Cc: Bjorn Andersson Signed-off-by: Johan Hovold Reviewed-by: Bjorn Andersson Reviewed-by: Dmitry Baryshkov Acked-by: Vinod Koul Acked-by: Neil Armstrong Link: https://lore.kernel.org/r/20240217150228.5788-7-johan+linaro@kernel.org Signed-off-by: Vinod Koul --- drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c index e19d6a084f10..17c4ad7553a5 100644 --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c +++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c @@ -3562,10 +3562,6 @@ static int qmp_combo_probe(struct platform_device *pdev) if (ret) return ret; - ret = qmp_combo_typec_switch_register(qmp); - 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) { @@ -3585,6 +3581,10 @@ static int qmp_combo_probe(struct platform_device *pdev) if (ret) goto err_node_put; + ret = qmp_combo_typec_switch_register(qmp); + if (ret) + goto err_node_put; + ret = drm_aux_bridge_register(dev); if (ret) goto err_node_put;