The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 11bb2ffb679399f99041540cf662409905179e3a # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024090121-distress-disengage-545d@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

11bb2ffb6793 ("usb: typec: ucsi: Move unregister out of atomic section") 584e8df58942 ("usb: typec: ucsi: extract common code for command handling") e1870c17e550 ("usb: typec: ucsi: inline ucsi_read_message_in") 5e9c1662a89b ("usb: typec: ucsi: rework command execution functions") 467399d989d7 ("usb: typec: ucsi: split read operation") 13f2ec3115c8 ("usb: typec: ucsi: simplify command sending API") a7d2fa776976 ("usb: typec: ucsi: move ucsi_acknowledge() from ucsi_read_error()") f7697db8b1b3 ("Merge 6.10-rc6 into usb-next")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 11bb2ffb679399f99041540cf662409905179e3a Mon Sep 17 00:00:00 2001 From: Bjorn Andersson quic_bjorande@quicinc.com Date: Tue, 20 Aug 2024 13:29:31 -0700 Subject: [PATCH] usb: typec: ucsi: Move unregister out of atomic section

Commit '9329933699b3 ("soc: qcom: pmic_glink: Make client-lock non-sleeping")' moved the pmic_glink client list under a spinlock, as it is accessed by the rpmsg/glink callback, which in turn is invoked from IRQ context.

This means that ucsi_unregister() is now called from atomic context, which isn't feasible as it's expecting a sleepable context. An effort is under way to get GLINK to invoke its callbacks in a sleepable context, but until then lets schedule the unregistration.

A side effect of this is that ucsi_unregister() can now happen after the remote processor, and thereby the communication link with it, is gone. pmic_glink_send() is amended with a check to avoid the resulting NULL pointer dereference. This does however result in the user being informed about this error by the following entry in the kernel log:

ucsi_glink.pmic_glink_ucsi pmic_glink.ucsi.0: failed to send UCSI write request: -5

Fixes: 9329933699b3 ("soc: qcom: pmic_glink: Make client-lock non-sleeping") Cc: stable@vger.kernel.org Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Reviewed-by: Neil Armstrong neil.armstrong@linaro.org Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Tested-by: Amit Pundir amit.pundir@linaro.org Reviewed-by: Johan Hovold johan+linaro@kernel.org Tested-by: Johan Hovold johan+linaro@kernel.org Signed-off-by: Bjorn Andersson quic_bjorande@quicinc.com Link: https://lore.kernel.org/r/20240820-pmic-glink-v6-11-races-v3-2-eec53c750a04@... Signed-off-by: Bjorn Andersson andersson@kernel.org

diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c index 53b176d04fbd..b218460219b7 100644 --- a/drivers/soc/qcom/pmic_glink.c +++ b/drivers/soc/qcom/pmic_glink.c @@ -112,8 +112,16 @@ EXPORT_SYMBOL_GPL(pmic_glink_client_register); int pmic_glink_send(struct pmic_glink_client *client, void *data, size_t len) { struct pmic_glink *pg = client->pg; + int ret;

- return rpmsg_send(pg->ept, data, len); + mutex_lock(&pg->state_lock); + if (!pg->ept) + ret = -ECONNRESET; + else + ret = rpmsg_send(pg->ept, data, len); + mutex_unlock(&pg->state_lock); + + return ret; } EXPORT_SYMBOL_GPL(pmic_glink_send);

diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c index f6f4fae40399..6aace19d595b 100644 --- a/drivers/usb/typec/ucsi/ucsi_glink.c +++ b/drivers/usb/typec/ucsi/ucsi_glink.c @@ -68,6 +68,9 @@ struct pmic_glink_ucsi {

struct work_struct notify_work; struct work_struct register_work; + spinlock_t state_lock; + bool ucsi_registered; + bool pd_running;

u8 read_buf[UCSI_BUF_SIZE]; }; @@ -244,8 +247,20 @@ static void pmic_glink_ucsi_notify(struct work_struct *work) static void pmic_glink_ucsi_register(struct work_struct *work) { struct pmic_glink_ucsi *ucsi = container_of(work, struct pmic_glink_ucsi, register_work); + unsigned long flags; + bool pd_running;

- ucsi_register(ucsi->ucsi); + spin_lock_irqsave(&ucsi->state_lock, flags); + pd_running = ucsi->pd_running; + spin_unlock_irqrestore(&ucsi->state_lock, flags); + + if (!ucsi->ucsi_registered && pd_running) { + ucsi_register(ucsi->ucsi); + ucsi->ucsi_registered = true; + } else if (ucsi->ucsi_registered && !pd_running) { + ucsi_unregister(ucsi->ucsi); + ucsi->ucsi_registered = false; + } }

static void pmic_glink_ucsi_callback(const void *data, size_t len, void *priv) @@ -269,11 +284,12 @@ static void pmic_glink_ucsi_callback(const void *data, size_t len, void *priv) static void pmic_glink_ucsi_pdr_notify(void *priv, int state) { struct pmic_glink_ucsi *ucsi = priv; + unsigned long flags;

- if (state == SERVREG_SERVICE_STATE_UP) - schedule_work(&ucsi->register_work); - else if (state == SERVREG_SERVICE_STATE_DOWN) - ucsi_unregister(ucsi->ucsi); + spin_lock_irqsave(&ucsi->state_lock, flags); + ucsi->pd_running = (state == SERVREG_SERVICE_STATE_UP); + spin_unlock_irqrestore(&ucsi->state_lock, flags); + schedule_work(&ucsi->register_work); }

static void pmic_glink_ucsi_destroy(void *data) @@ -320,6 +336,7 @@ static int pmic_glink_ucsi_probe(struct auxiliary_device *adev, INIT_WORK(&ucsi->register_work, pmic_glink_ucsi_register); init_completion(&ucsi->read_ack); init_completion(&ucsi->write_ack); + spin_lock_init(&ucsi->state_lock); mutex_init(&ucsi->lock);

ucsi->ucsi = ucsi_create(dev, &pmic_glink_ucsi_ops);