From: André Draszik andre.draszik@linaro.org
[ Upstream commit 31611223fb34a3e9320cdfc4f4395072a13ea78e ]
This driver calls enable_irq_wake() during probe() unconditionally, and never issues the required corresponding disable_irq_wake() to disable hardware interrupt wakeup signals.
Additionally, whether or not a device should wake-up the system is meant to be a policy decision based on sysfs (.../power/wakeup) in the first place.
Update the driver to use the standard approach to enable/disable IRQ wake during the suspend/resume callbacks. This solves both issues described above.
Signed-off-by: André Draszik andre.draszik@linaro.org Reviewed-by: Badhri Jagan Sridharan badhri@google.com Link: https://lore.kernel.org/r/20250707-max77759-irq-wake-v1-1-d367f633e4bc@linar... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---
LLM Generated explanations, may be completely bogus:
**Backport Status: YES**
This commit should be backported to stable kernel trees for the following reasons:
1. **Clear Bug Fix**: The commit fixes a resource management bug where `enable_irq_wake()` is called during probe without a corresponding `disable_irq_wake()`. This violates the kernel's IRQ wake API usage requirements, leading to: - Resource leak in the IRQ subsystem - Incorrect wake behavior that cannot be controlled via sysfs - Potential system power management issues
2. **Small and Contained Change**: The fix is minimal and well- contained: - Removes the problematic `max_tcpci_init_alert()` function - Moves IRQ request directly into probe - Adds proper suspend/resume callbacks with correct `enable_irq_wake()`/`disable_irq_wake()` pairing - Total change is about 40 lines of straightforward code
3. **Low Risk of Regression**: - The change follows established kernel patterns for IRQ wake handling in PM callbacks - Similar patterns exist in other USB Type-C drivers (e.g., fusb302.c uses suspend/resume for IRQ wake) - The fix only affects power management behavior, not core functionality - Uses `device_may_wakeup()` to properly check policy before enabling wake
4. **Clear Impact on Users**: - Without this fix, devices cannot properly control wake-on-USB-C events through sysfs - The unconditional `enable_irq_wake()` means the device will always wake the system on USB-C events, regardless of user preference - This affects power consumption and battery life on systems with USB Type-C
5. **No Architectural Changes**: The commit: - Doesn't introduce new features - Doesn't change any APIs or interfaces - Simply fixes incorrect usage of existing kernel APIs - Maintains backward compatibility
The commit message clearly explains the problem and solution, the code changes are minimal and correct, and it fixes a real bug that affects system power management behavior. This is exactly the type of fix that stable kernels should receive.
drivers/usb/typec/tcpm/tcpci_maxim_core.c | 46 +++++++++++++++-------- 1 file changed, 30 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpci_maxim_core.c b/drivers/usb/typec/tcpm/tcpci_maxim_core.c index 648311f5e3cf..eeaf79e97261 100644 --- a/drivers/usb/typec/tcpm/tcpci_maxim_core.c +++ b/drivers/usb/typec/tcpm/tcpci_maxim_core.c @@ -421,21 +421,6 @@ static irqreturn_t max_tcpci_isr(int irq, void *dev_id) return IRQ_WAKE_THREAD; }
-static int max_tcpci_init_alert(struct max_tcpci_chip *chip, struct i2c_client *client) -{ - int ret; - - ret = devm_request_threaded_irq(chip->dev, client->irq, max_tcpci_isr, max_tcpci_irq, - (IRQF_TRIGGER_LOW | IRQF_ONESHOT), dev_name(chip->dev), - chip); - - if (ret < 0) - return ret; - - enable_irq_wake(client->irq); - return 0; -} - static int max_tcpci_start_toggling(struct tcpci *tcpci, struct tcpci_data *tdata, enum typec_cc_status cc) { @@ -532,7 +517,9 @@ static int max_tcpci_probe(struct i2c_client *client)
chip->port = tcpci_get_tcpm_port(chip->tcpci);
- ret = max_tcpci_init_alert(chip, client); + ret = devm_request_threaded_irq(&client->dev, client->irq, max_tcpci_isr, max_tcpci_irq, + (IRQF_TRIGGER_LOW | IRQF_ONESHOT), dev_name(chip->dev), + chip); if (ret < 0) return dev_err_probe(&client->dev, ret, "IRQ initialization failed\n"); @@ -541,6 +528,32 @@ static int max_tcpci_probe(struct i2c_client *client) return 0; }
+#ifdef CONFIG_PM_SLEEP +static int max_tcpci_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + int ret = 0; + + if (client->irq && device_may_wakeup(dev)) + ret = disable_irq_wake(client->irq); + + return ret; +} + +static int max_tcpci_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + int ret = 0; + + if (client->irq && device_may_wakeup(dev)) + ret = enable_irq_wake(client->irq); + + return ret; +} +#endif /* CONFIG_PM_SLEEP */ + +static SIMPLE_DEV_PM_OPS(max_tcpci_pm_ops, max_tcpci_suspend, max_tcpci_resume); + static const struct i2c_device_id max_tcpci_id[] = { { "maxtcpc" }, { } @@ -559,6 +572,7 @@ static struct i2c_driver max_tcpci_i2c_driver = { .driver = { .name = "maxtcpc", .of_match_table = of_match_ptr(max_tcpci_of_match), + .pm = &max_tcpci_pm_ops, }, .probe = max_tcpci_probe, .id_table = max_tcpci_id,