@@ -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)
@@ -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 &
@@ -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
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: <stable@vger.kernel.org> Signed-off-by: Xu Yang <xu.yang_2@nxp.com> --- changes since v1: - modify description for mutex member - wrap role variable in ci_handle_id_switch() too --- 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(-)