From 39c0f19aa4e8d115ddd2466df1c4dfbc4ab4fdc9 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 20 May 2025 12:44:40 +0200 Subject: [PATCH] 6.12-stable patches added patches: usb-typec-ucsi-displayport-fix-deadlock.patch --- queue-6.12/series | 1 + ...-typec-ucsi-displayport-fix-deadlock.patch | 156 ++++++++++++++++++ 2 files changed, 157 insertions(+) create mode 100644 queue-6.12/usb-typec-ucsi-displayport-fix-deadlock.patch diff --git a/queue-6.12/series b/queue-6.12/series index 8fe5755f20..0a16035026 100644 --- a/queue-6.12/series +++ b/queue-6.12/series @@ -144,3 +144,4 @@ bluetooth-btnxpuart-fix-kernel-panic-during-fw-release.patch drm-fbdev-dma-support-struct-drm_driver.fbdev_probe.patch drm-panel-mipi-dbi-run-drm-default-client-setup.patch drm-tiny-panel-mipi-dbi-use-drm_client_setup_with_fourcc.patch +usb-typec-ucsi-displayport-fix-deadlock.patch diff --git a/queue-6.12/usb-typec-ucsi-displayport-fix-deadlock.patch b/queue-6.12/usb-typec-ucsi-displayport-fix-deadlock.patch new file mode 100644 index 0000000000..cefefd2871 --- /dev/null +++ b/queue-6.12/usb-typec-ucsi-displayport-fix-deadlock.patch @@ -0,0 +1,156 @@ +From 364618c89d4c57c85e5fc51a2446cd939bf57802 Mon Sep 17 00:00:00 2001 +From: Andrei Kuchynski +Date: Thu, 24 Apr 2025 08:44:28 +0000 +Subject: usb: typec: ucsi: displayport: Fix deadlock + +From: Andrei Kuchynski + +commit 364618c89d4c57c85e5fc51a2446cd939bf57802 upstream. + +This patch introduces the ucsi_con_mutex_lock / ucsi_con_mutex_unlock +functions to the UCSI driver. ucsi_con_mutex_lock ensures the connector +mutex is only locked if a connection is established and the partner pointer +is valid. This resolves a deadlock scenario where +ucsi_displayport_remove_partner holds con->mutex waiting for +dp_altmode_work to complete while dp_altmode_work attempts to acquire it. + +Cc: stable +Fixes: af8622f6a585 ("usb: typec: ucsi: Support for DisplayPort alt mode") +Signed-off-by: Andrei Kuchynski +Reviewed-by: Heikki Krogerus +Link: https://lore.kernel.org/r/20250424084429.3220757-2-akuchynski@chromium.org +Signed-off-by: Greg Kroah-Hartman +--- + drivers/usb/typec/ucsi/displayport.c | 19 +++++++++++-------- + drivers/usb/typec/ucsi/ucsi.c | 34 ++++++++++++++++++++++++++++++++++ + drivers/usb/typec/ucsi/ucsi.h | 2 ++ + 3 files changed, 47 insertions(+), 8 deletions(-) + +--- a/drivers/usb/typec/ucsi/displayport.c ++++ b/drivers/usb/typec/ucsi/displayport.c +@@ -54,7 +54,8 @@ static int ucsi_displayport_enter(struct + u8 cur = 0; + int ret; + +- mutex_lock(&dp->con->lock); ++ if (!ucsi_con_mutex_lock(dp->con)) ++ return -ENOTCONN; + + if (!dp->override && dp->initialized) { + const struct typec_altmode *p = typec_altmode_get_partner(alt); +@@ -100,7 +101,7 @@ static int ucsi_displayport_enter(struct + schedule_work(&dp->work); + ret = 0; + err_unlock: +- mutex_unlock(&dp->con->lock); ++ ucsi_con_mutex_unlock(dp->con); + + return ret; + } +@@ -112,7 +113,8 @@ static int ucsi_displayport_exit(struct + u64 command; + int ret = 0; + +- mutex_lock(&dp->con->lock); ++ if (!ucsi_con_mutex_lock(dp->con)) ++ return -ENOTCONN; + + if (!dp->override) { + const struct typec_altmode *p = typec_altmode_get_partner(alt); +@@ -144,7 +146,7 @@ static int ucsi_displayport_exit(struct + schedule_work(&dp->work); + + out_unlock: +- mutex_unlock(&dp->con->lock); ++ ucsi_con_mutex_unlock(dp->con); + + return ret; + } +@@ -202,20 +204,21 @@ static int ucsi_displayport_vdm(struct t + int cmd = PD_VDO_CMD(header); + int svdm_version; + +- mutex_lock(&dp->con->lock); ++ if (!ucsi_con_mutex_lock(dp->con)) ++ return -ENOTCONN; + + if (!dp->override && dp->initialized) { + const struct typec_altmode *p = typec_altmode_get_partner(alt); + + dev_warn(&p->dev, + "firmware doesn't support alternate mode overriding\n"); +- mutex_unlock(&dp->con->lock); ++ ucsi_con_mutex_unlock(dp->con); + return -EOPNOTSUPP; + } + + svdm_version = typec_altmode_get_svdm_version(alt); + if (svdm_version < 0) { +- mutex_unlock(&dp->con->lock); ++ ucsi_con_mutex_unlock(dp->con); + return svdm_version; + } + +@@ -259,7 +262,7 @@ static int ucsi_displayport_vdm(struct t + break; + } + +- mutex_unlock(&dp->con->lock); ++ ucsi_con_mutex_unlock(dp->con); + + return 0; + } +--- a/drivers/usb/typec/ucsi/ucsi.c ++++ b/drivers/usb/typec/ucsi/ucsi.c +@@ -1904,6 +1904,40 @@ void ucsi_set_drvdata(struct ucsi *ucsi, + EXPORT_SYMBOL_GPL(ucsi_set_drvdata); + + /** ++ * ucsi_con_mutex_lock - Acquire the connector mutex ++ * @con: The connector interface to lock ++ * ++ * Returns true on success, false if the connector is disconnected ++ */ ++bool ucsi_con_mutex_lock(struct ucsi_connector *con) ++{ ++ bool mutex_locked = false; ++ bool connected = true; ++ ++ while (connected && !mutex_locked) { ++ mutex_locked = mutex_trylock(&con->lock) != 0; ++ connected = con->status.flags & UCSI_CONSTAT_CONNECTED; ++ if (connected && !mutex_locked) ++ msleep(20); ++ } ++ ++ connected = connected && con->partner; ++ if (!connected && mutex_locked) ++ mutex_unlock(&con->lock); ++ ++ return connected; ++} ++ ++/** ++ * ucsi_con_mutex_unlock - Release the connector mutex ++ * @con: The connector interface to unlock ++ */ ++void ucsi_con_mutex_unlock(struct ucsi_connector *con) ++{ ++ mutex_unlock(&con->lock); ++} ++ ++/** + * ucsi_create - Allocate UCSI instance + * @dev: Device interface to the PPM (Platform Policy Manager) + * @ops: I/O routines +--- a/drivers/usb/typec/ucsi/ucsi.h ++++ b/drivers/usb/typec/ucsi/ucsi.h +@@ -91,6 +91,8 @@ int ucsi_register(struct ucsi *ucsi); + void ucsi_unregister(struct ucsi *ucsi); + void *ucsi_get_drvdata(struct ucsi *ucsi); + void ucsi_set_drvdata(struct ucsi *ucsi, void *data); ++bool ucsi_con_mutex_lock(struct ucsi_connector *con); ++void ucsi_con_mutex_unlock(struct ucsi_connector *con); + + void ucsi_connector_change(struct ucsi *ucsi, u8 num); + -- 2.47.3