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-rw-r--r--include/linux/hid.h46
1 files changed, 45 insertions, 1 deletions
diff --git a/include/linux/hid.h b/include/linux/hid.h
index e14b465b1146..895b85639dec 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -456,7 +456,8 @@ struct hid_device { /* device report descriptor */
unsigned country; /* HID country */
struct hid_report_enum report_enum[HID_REPORT_TYPES];
- struct semaphore driver_lock; /* protects the current driver */
+ struct semaphore driver_lock; /* protects the current driver, except during input */
+ struct semaphore driver_input_lock; /* protects the current driver */
struct device dev; /* device */
struct hid_driver *driver;
struct hid_ll_driver *ll_driver;
@@ -477,6 +478,7 @@ struct hid_device { /* device report descriptor */
unsigned int status; /* see STAT flags above */
unsigned claimed; /* Claimed by hidinput, hiddev? */
unsigned quirks; /* Various quirks the device can pull on us */
+ bool io_started; /* Protected by driver_lock. If IO has started */
struct list_head inputs; /* The list of inputs */
void *hiddev; /* The hiddev structure */
@@ -599,6 +601,10 @@ struct hid_usage_id {
* @resume: invoked on resume if device was not reset (NULL means nop)
* @reset_resume: invoked on resume if device was reset (NULL means nop)
*
+ * probe should return -errno on error, or 0 on success. During probe,
+ * input will not be passed to raw_event unless hid_device_io_start is
+ * called.
+ *
* raw_event and event should return 0 on no action performed, 1 when no
* further processing should be done and negative on error
*
@@ -738,6 +744,44 @@ const struct hid_device_id *hid_match_id(struct hid_device *hdev,
s32 hid_snto32(__u32 value, unsigned n);
/**
+ * hid_device_io_start - enable HID input during probe, remove
+ *
+ * @hid - the device
+ *
+ * This should only be called during probe or remove and only be
+ * called by the thread calling probe or remove. It will allow
+ * incoming packets to be delivered to the driver.
+ */
+static inline void hid_device_io_start(struct hid_device *hid) {
+ if (hid->io_started) {
+ dev_warn(&hid->dev, "io already started");
+ return;
+ }
+ hid->io_started = true;
+ up(&hid->driver_input_lock);
+}
+
+/**
+ * hid_device_io_stop - disable HID input during probe, remove
+ *
+ * @hid - the device
+ *
+ * Should only be called after hid_device_io_start. It will prevent
+ * incoming packets from going to the driver for the duration of
+ * probe, remove. If called during probe, packets will still go to the
+ * driver after probe is complete. This function should only be called
+ * by the thread calling probe or remove.
+ */
+static inline void hid_device_io_stop(struct hid_device *hid) {
+ if (!hid->io_started) {
+ dev_warn(&hid->dev, "io already stopped");
+ return;
+ }
+ hid->io_started = false;
+ down(&hid->driver_input_lock);
+}
+
+/**
* hid_map_usage - map usage input bits
*
* @hidinput: hidinput which we are interested in