Skip to contentSkip to conversation

patch "usb: chipidea: core: fix possible concurrent when switch role" added to usb-linus

PATCH [email protected] 1 participant 1 message Mar 23, 2023

Subsystems (3)
Stable branch USB Chipidea USB high speed dual role controller
lore
Share & tools
lore

[email protected]

author maintainer Applied
#0 lore raw

This is a note to let you know that I've just added the patch titled

usb: chipidea: core: fix possible concurrent when switch role

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 451b15ed138ec15bffbebb58a00ebdd884c3e659 Mon Sep 17 00:00:00 2001
From: Xu Yang <[email protected]>
Date: Fri, 17 Mar 2023 14:15:16 +0800
Subject: usb: chipidea: core: fix possible concurrent when switch role

The user may call role_store() when driver is handling ci_handle_id_switch() which is triggerred by otg event or power lost event. Unfortunately, the controller may go into chaos in this case. Fix this by protecting it with mutex lock.

Fixes a932a8041ff9 ("usb: chipidea: core: add sysfs group")
cc <[email protected]>
Acked-by Peter Chen <[email protected]>
Signed-off-by Xu Yang <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/usb/chipidea/ci.h   | 2 ++
 drivers/usb/chipidea/core.c | 8 +++++++-
 drivers/usb/chipidea/otg.c  | 5 ++++-
 3 files changed, 13 insertions(+), 2 deletions(-)
drivers/usb/chipidea/ci.h +2 -0
index 005c67cb3afb..f210b7489fd5 100644
@@ -208,6 +208,7 @@ struct hw_bank {
  * @in_lpm: if the core in low power mode
  * @wakeup_int: if wakeup interrupt occur
  * @rev: The revision number for controller
+ * @mutex: protect code from concorrent running when doing role switch
  */
 struct ci_hdrc {
 	struct device			*dev;

@@ -260,6 +261,7 @@ struct ci_hdrc {
 	bool				in_lpm;
 	bool				wakeup_int;
 	enum ci_revision		rev;
+	struct mutex                    mutex;
 };
 
 static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci)
drivers/usb/chipidea/core.c +7 -1
index b6f2a41de20e..281fc51720ce 100644
@@ -987,8 +987,12 @@ static ssize_t role_store(struct device *dev,
 	if (role == CI_ROLE_END)
 		return -EINVAL;
 
-	if (role == ci->role)
+	mutex_lock(&ci->mutex);
+
+	if (role == ci->role) {
+		mutex_unlock(&ci->mutex);
 		return n;
+	}
 
 	pm_runtime_get_sync(dev);
 	disable_irq(ci->irq);

@@ -998,6 +1002,7 @@ static ssize_t role_store(struct device *dev,
 		ci_handle_vbus_change(ci);
 	enable_irq(ci->irq);
 	pm_runtime_put_sync(dev);
+	mutex_unlock(&ci->mutex);
 
 	return (ret == 0) ? n : ret;
 }

@@ -1033,6 +1038,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	spin_lock_init(&ci->lock);
+	mutex_init(&ci->mutex);
 	ci->dev = dev;
 	ci->platdata = dev_get_platdata(dev);
 	ci->imx28_write_fix = !!(ci->platdata->flags &
drivers/usb/chipidea/otg.c +4 -1
index 622c3b68aa1e..f5490f2a5b6b 100644
@@ -167,8 +167,10 @@ static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci)
 
 void ci_handle_id_switch(struct ci_hdrc *ci)
 {
-	enum ci_role role = ci_otg_role(ci);
+	enum ci_role role;
 
+	mutex_lock(&ci->mutex);
+	role = ci_otg_role(ci);
 	if (role != ci->role) {
 		dev_dbg(ci->dev, "switching from %s to %s\n",
 			ci_role(ci)->name, ci->roles[role]->name);

@@ -198,6 +200,7 @@ void ci_handle_id_switch(struct ci_hdrc *ci)
 		if (role == CI_ROLE_GADGET)
 			ci_handle_vbus_change(ci);
 	}
+	mutex_unlock(&ci->mutex);
 }
 /**
  * ci_otg_work - perform otg (vbus/id) event handle
Signature · 1 line
2.40.0