corsair_void_process_receiver can be called from an interrupt context, locking battery_mutex in it was causing a kernel panic. Fix it by moving the critical section into its own work, sharing this work with battery_add_work and battery_remove_work to remove the need for any locking

Closes: https://bugzilla.suse.com/show_bug.cgi?id=1236843 Fixes: 6ea2a6fd3872 ("HID: corsair-void: Add Corsair Void headset family driver") Cc: stable@vger.kernel.org Signed-off-by: Stuart Hayhurst stuart.a.hayhurst@gmail.com ---

v2 -> v3: - Use an enum instead of a define for battery flag values - Use an integer instead of BIT() for the bit index - Drop unhelpful comments - Simplify corsair_void_battery_work_handler logic - Remove extra newline in commit message v1 -> v2: - Actually remove the mutex

--- drivers/hid/hid-corsair-void.c | 83 ++++++++++++++++++---------------- 1 file changed, 43 insertions(+), 40 deletions(-)

diff --git a/drivers/hid/hid-corsair-void.c b/drivers/hid/hid-corsair-void.c index 56e858066c3c..afbd67aa9719 100644 --- a/drivers/hid/hid-corsair-void.c +++ b/drivers/hid/hid-corsair-void.c @@ -71,11 +71,9 @@

#include <linux/bitfield.h> #include <linux/bitops.h> -#include <linux/cleanup.h> #include <linux/device.h> #include <linux/hid.h> #include <linux/module.h> -#include <linux/mutex.h> #include <linux/power_supply.h> #include <linux/usb.h> #include <linux/workqueue.h> @@ -120,6 +118,12 @@ enum { CORSAIR_VOID_BATTERY_CHARGING = 5, };

+enum { + CORSAIR_VOID_ADD_BATTERY = 0, + CORSAIR_VOID_REMOVE_BATTERY = 1, + CORSAIR_VOID_UPDATE_BATTERY = 2, +}; + static enum power_supply_property corsair_void_battery_props[] = { POWER_SUPPLY_PROP_STATUS, POWER_SUPPLY_PROP_PRESENT, @@ -155,12 +159,12 @@ struct corsair_void_drvdata {

struct power_supply *battery; struct power_supply_desc battery_desc; - struct mutex battery_mutex;

struct delayed_work delayed_status_work; struct delayed_work delayed_firmware_work; - struct work_struct battery_remove_work; - struct work_struct battery_add_work; + + unsigned long battery_work_flags; + struct work_struct battery_work; };

/* @@ -260,11 +264,9 @@ static void corsair_void_process_receiver(struct corsair_void_drvdata *drvdata,

/* Inform power supply if battery values changed */ if (memcmp(&orig_battery_data, battery_data, sizeof(*battery_data))) { - scoped_guard(mutex, &drvdata->battery_mutex) { - if (drvdata->battery) { - power_supply_changed(drvdata->battery); - } - } + set_bit(CORSAIR_VOID_UPDATE_BATTERY, + &drvdata->battery_work_flags); + schedule_work(&drvdata->battery_work); } }

@@ -536,29 +538,11 @@ static void corsair_void_firmware_work_handler(struct work_struct *work)

}

-static void corsair_void_battery_remove_work_handler(struct work_struct *work) -{ - struct corsair_void_drvdata *drvdata; - - drvdata = container_of(work, struct corsair_void_drvdata, - battery_remove_work); - scoped_guard(mutex, &drvdata->battery_mutex) { - if (drvdata->battery) { - power_supply_unregister(drvdata->battery); - drvdata->battery = NULL; - } - } -} - -static void corsair_void_battery_add_work_handler(struct work_struct *work) +static void corsair_void_add_battery(struct corsair_void_drvdata *drvdata) { - struct corsair_void_drvdata *drvdata; struct power_supply_config psy_cfg = {}; struct power_supply *new_supply;

- drvdata = container_of(work, struct corsair_void_drvdata, - battery_add_work); - guard(mutex)(&drvdata->battery_mutex); if (drvdata->battery) return;

@@ -583,16 +567,42 @@ static void corsair_void_battery_add_work_handler(struct work_struct *work) drvdata->battery = new_supply; }

+static void corsair_void_battery_work_handler(struct work_struct *work) +{ + struct corsair_void_drvdata *drvdata = container_of(work, + struct corsair_void_drvdata, battery_work); + + bool add_battery = test_and_clear_bit(CORSAIR_VOID_ADD_BATTERY, + &drvdata->battery_work_flags); + bool remove_battery = test_and_clear_bit(CORSAIR_VOID_REMOVE_BATTERY, + &drvdata->battery_work_flags); + bool update_battery = test_and_clear_bit(CORSAIR_VOID_UPDATE_BATTERY, + &drvdata->battery_work_flags); + + if (add_battery && !remove_battery) { + corsair_void_add_battery(drvdata); + } else if (remove_battery && !add_battery && drvdata->battery) { + power_supply_unregister(drvdata->battery); + drvdata->battery = NULL; + } + + if (update_battery && drvdata->battery) + power_supply_changed(drvdata->battery); + +} + static void corsair_void_headset_connected(struct corsair_void_drvdata *drvdata) { - schedule_work(&drvdata->battery_add_work); + set_bit(CORSAIR_VOID_ADD_BATTERY, &drvdata->battery_work_flags); + schedule_work(&drvdata->battery_work); schedule_delayed_work(&drvdata->delayed_firmware_work, msecs_to_jiffies(100)); }

static void corsair_void_headset_disconnected(struct corsair_void_drvdata *drvdata) { - schedule_work(&drvdata->battery_remove_work); + set_bit(CORSAIR_VOID_REMOVE_BATTERY, &drvdata->battery_work_flags); + schedule_work(&drvdata->battery_work);

corsair_void_set_unknown_wireless_data(drvdata); corsair_void_set_unknown_batt(drvdata); @@ -678,13 +688,7 @@ static int corsair_void_probe(struct hid_device *hid_dev, drvdata->battery_desc.get_property = corsair_void_battery_get_property;

drvdata->battery = NULL; - INIT_WORK(&drvdata->battery_remove_work, - corsair_void_battery_remove_work_handler); - INIT_WORK(&drvdata->battery_add_work, - corsair_void_battery_add_work_handler); - ret = devm_mutex_init(drvdata->dev, &drvdata->battery_mutex); - if (ret) - return ret; + INIT_WORK(&drvdata->battery_work, corsair_void_battery_work_handler);

ret = sysfs_create_group(&hid_dev->dev.kobj, &corsair_void_attr_group); if (ret) @@ -721,8 +725,7 @@ static void corsair_void_remove(struct hid_device *hid_dev) struct corsair_void_drvdata *drvdata = hid_get_drvdata(hid_dev);

hid_hw_stop(hid_dev); - cancel_work_sync(&drvdata->battery_remove_work); - cancel_work_sync(&drvdata->battery_add_work); + cancel_work_sync(&drvdata->battery_work); if (drvdata->battery) power_supply_unregister(drvdata->battery);