nzxt-kraken3: Reinit status request completion under a spinlock

Signed-off-by: Aleksa Savic <[email protected]>

nzxt-kraken3.c

@@ -15,6 +15,7 @@
 #include <linux/jiffies.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/spinlock.h>
 #include <linux/wait.h>
 #include <asm/unaligned.h>
 
@@ -117,6 +118,8 @@ struct kraken3_data {
  * was processed after requesting one.
  */
  struct completion status_report_processed;
+ /* For locking the above completion */
+ spinlock_t status_completion_lock;
 
  u8 *buffer;
  struct kraken3_channel_info channel_info[2]; /* Pump and fan */
@@ -256,6 +259,7 @@ static int kraken3_read_z53(struct kraken3_data *priv)
 {
  int ret;
  ulong remaining_time;
+ unsigned long flags;
 
  /* In the case of multiple concurrent readers, request a status report only if necessary */
  if (!mutex_lock_interruptible(&priv->z53_status_request_lock)) {
@@ -264,6 +268,14 @@ static int kraken3_read_z53(struct kraken3_data *priv)
  goto unlock_and_return;
  }
 
+ /*
+ * Disable interrupts for a moment to safely reinit the completion,
+ * as hidraw calls could have allowed one or more readers to complete().
+ */
+ spin_lock_irqsave(&priv->status_completion_lock, flags);
+ reinit_completion(&priv->status_report_processed);
+ spin_unlock_irqrestore(&priv->status_completion_lock, flags);
+
  /* Send command for getting status */
  ret = kraken3_write_expanded(priv, z53_get_status_cmd, Z53_GET_STATUS_CMD_LENGTH);
  if (ret < 0) {
@@ -726,6 +738,7 @@ static int kraken3_raw_event(struct hid_device *hdev, struct hid_report *report,
 {
  int i;
  struct kraken3_data *priv = hid_get_drvdata(hdev);
+ unsigned long flags;
 
  if (size < MIN_REPORT_LENGTH)
  return 0;
@@ -773,7 +786,9 @@ static int kraken3_raw_event(struct hid_device *hdev, struct hid_report *report,
  priv->channel_info[1].reported_duty =
  kraken3_percent_to_pwm(data[Z53_FAN_DUTY_OFFSET]);
 
+ spin_lock_irqsave(&priv->status_completion_lock, flags);
  complete(&priv->status_report_processed);
+ spin_unlock_irqrestore(&priv->status_completion_lock, flags);
  }
 
  priv->updated = jiffies;
@@ -915,6 +930,7 @@ static int kraken3_probe(struct hid_device *hdev, const struct hid_device_id *id
  init_waitqueue_head(&priv->z53_reader_wq);
  init_completion(&priv->fw_version_processed);
  init_completion(&priv->status_report_processed);
+ spin_lock_init(&priv->status_completion_lock);
 
  ret = kraken3_init_device(hdev);
  if (ret) {