diff options
| -rw-r--r-- | drivers/hid/hid-core.c | 24 | ||||
| -rw-r--r-- | include/linux/hid.h | 46 |
2 files changed, 66 insertions, 4 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index ff75cabf7393..680068c0c46a 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1267,7 +1267,7 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i if (!hid) return -ENODEV; - if (down_trylock(&hid->driver_lock)) + if (down_trylock(&hid->driver_input_lock)) return -EBUSY; if (!hid->driver) { @@ -1324,7 +1324,7 @@ nomem: ret = hid_report_raw_event(hid, type, data, size, interrupt); unlock: - up(&hid->driver_lock); + up(&hid->driver_input_lock); return ret; } EXPORT_SYMBOL_GPL(hid_input_report); @@ -1845,6 +1845,11 @@ static int hid_device_probe(struct device *dev) if (down_interruptible(&hdev->driver_lock)) return -EINTR; + if (down_interruptible(&hdev->driver_input_lock)) { + ret = -EINTR; + goto unlock_driver_lock; + } + hdev->io_started = false; if (!hdev->driver) { id = hid_match_device(hdev, hdrv); @@ -1867,6 +1872,9 @@ static int hid_device_probe(struct device *dev) } } unlock: + if (!hdev->io_started) + up(&hdev->driver_input_lock); +unlock_driver_lock: up(&hdev->driver_lock); return ret; } @@ -1875,9 +1883,15 @@ static int hid_device_remove(struct device *dev) { struct hid_device *hdev = container_of(dev, struct hid_device, dev); struct hid_driver *hdrv; + int ret = 0; if (down_interruptible(&hdev->driver_lock)) return -EINTR; + if (down_interruptible(&hdev->driver_input_lock)) { + ret = -EINTR; + goto unlock_driver_lock; + } + hdev->io_started = false; hdrv = hdev->driver; if (hdrv) { @@ -1889,8 +1903,11 @@ static int hid_device_remove(struct device *dev) hdev->driver = NULL; } + if (!hdev->io_started) + up(&hdev->driver_input_lock); +unlock_driver_lock: up(&hdev->driver_lock); - return 0; + return ret; } static ssize_t modalias_show(struct device *dev, struct device_attribute *a, @@ -2329,6 +2346,7 @@ struct hid_device *hid_allocate_device(void) init_waitqueue_head(&hdev->debug_wait); INIT_LIST_HEAD(&hdev->debug_list); sema_init(&hdev->driver_lock, 1); + sema_init(&hdev->driver_input_lock, 1); return hdev; } 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 |