From d487085006109e5981e059476818243759d2e925 Mon Sep 17 00:00:00 2001 From: Konrad Dybcio Date: Fri, 6 Mar 2026 12:20:14 +0100 Subject: [PATCH] soc: qcom: pmic_glink_altmode: Fix SVID=DP && unconnected edge case The commit referenced in Fixes started evaluating the value of alt_port->mux_ctrl before checking the active SVID. This led to drm_aux_hpd_bridge_notify() no longer being called for the 'DP unplug' case. Perhaps somewhat interestingly, the firmware sends a notification with SVID=DP, mux_ctrl=MUX_CTRL_STATE_NO_CONN and pin_assignment=0 on unplug. 'pin_assignment' was previously interpreted as a bitfield excerpt from the second byte of the DP pg_altmode payload (and stored as an u8). That value is used in pmic_glink_altmode_sc8280xp_notify(), decremented by 1 (DPAM_HPD_A). Previously, this would result in an u8 underflow that would rollover to 0xff (which prior to the Fixes patch would have caused a pmic_glink_altmode_safe() and 'disconnected' bridge notification). That check was removed, without a replacement. Resolve this issue by making sure the SID=DP && mux_ctrl=NO_CONN combo once again results in a HPD bridge notification. Fixes: 0539c5a6fdef ("soc: qcom: pmic_glink_altmode: Consume TBT3/USB4 mode notifications") Reported-by: Abel Vesa Tested-by: Abel Vesa Signed-off-by: Konrad Dybcio Link: https://lore.kernel.org/r/20260306-topic-pgaltmode_fixup-v1-1-ec154b2d8e89@oss.qualcomm.com Signed-off-by: Bjorn Andersson --- drivers/soc/qcom/pmic_glink_altmode.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/soc/qcom/pmic_glink_altmode.c b/drivers/soc/qcom/pmic_glink_altmode.c index d0afdcb96ee1..b496b88842a2 100644 --- a/drivers/soc/qcom/pmic_glink_altmode.c +++ b/drivers/soc/qcom/pmic_glink_altmode.c @@ -350,15 +350,17 @@ static void pmic_glink_altmode_worker(struct work_struct *work) typec_switch_set(alt_port->typec_switch, alt_port->orientation); - if (alt_port->mux_ctrl == MUX_CTRL_STATE_NO_CONN) { - pmic_glink_altmode_safe(altmode, alt_port); - } else if (alt_port->svid == USB_TYPEC_TBT_SID) { + if (alt_port->svid == USB_TYPEC_TBT_SID) { pmic_glink_altmode_enable_tbt(altmode, alt_port); } else if (alt_port->svid == USB_TYPEC_DP_SID) { - pmic_glink_altmode_enable_dp(altmode, alt_port, - alt_port->mode, - alt_port->hpd_state, - alt_port->hpd_irq); + if (alt_port->mux_ctrl == MUX_CTRL_STATE_NO_CONN) { + pmic_glink_altmode_safe(altmode, alt_port); + } else { + pmic_glink_altmode_enable_dp(altmode, alt_port, + alt_port->mode, + alt_port->hpd_state, + alt_port->hpd_irq); + } if (alt_port->hpd_state) conn_status = connector_status_connected; @@ -368,6 +370,8 @@ static void pmic_glink_altmode_worker(struct work_struct *work) drm_aux_hpd_bridge_notify(&alt_port->bridge->dev, conn_status); } else if (alt_port->mux_ctrl == MUX_CTRL_STATE_TUNNELING) { pmic_glink_altmode_enable_usb4(altmode, alt_port); + } else if (alt_port->mux_ctrl == MUX_CTRL_STATE_NO_CONN) { + pmic_glink_altmode_safe(altmode, alt_port); } else { pmic_glink_altmode_enable_usb(altmode, alt_port); } -- 2.47.3