diff options
| -rw-r--r-- | drivers/hid/hid-input.c | 80 | ||||
| -rw-r--r-- | include/linux/hid.h | 1 |
2 files changed, 80 insertions, 1 deletions
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 7480799e535c..308eee8fc7c3 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1137,6 +1137,74 @@ unsigned int hidinput_count_leds(struct hid_device *hid) } EXPORT_SYMBOL_GPL(hidinput_count_leds); +static void hidinput_led_worker(struct work_struct *work) +{ + struct hid_device *hid = container_of(work, struct hid_device, + led_work); + struct hid_field *field; + struct hid_report *report; + int len; + __u8 *buf; + + field = hidinput_get_led_field(hid); + if (!field) + return; + + /* + * field->report is accessed unlocked regarding HID core. So there might + * be another incoming SET-LED request from user-space, which changes + * the LED state while we assemble our outgoing buffer. However, this + * doesn't matter as hid_output_report() correctly converts it into a + * boolean value no matter what information is currently set on the LED + * field (even garbage). So the remote device will always get a valid + * request. + * And in case we send a wrong value, a next led worker is spawned + * for every SET-LED request so the following worker will send the + * correct value, guaranteed! + */ + + report = field->report; + + /* use custom SET_REPORT request if possible (asynchronous) */ + if (hid->ll_driver->request) + return hid->ll_driver->request(hid, report, HID_REQ_SET_REPORT); + + /* fall back to generic raw-output-report */ + len = ((report->size - 1) >> 3) + 1 + (report->id > 0); + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + return; + + hid_output_report(report, buf); + /* synchronous output report */ + hid->hid_output_raw_report(hid, buf, len, HID_OUTPUT_REPORT); + kfree(buf); +} + +static int hidinput_input_event(struct input_dev *dev, unsigned int type, + unsigned int code, int value) +{ + struct hid_device *hid = input_get_drvdata(dev); + struct hid_field *field; + int offset; + + if (type == EV_FF) + return input_ff_event(dev, type, code, value); + + if (type != EV_LED) + return -1; + + if ((offset = hidinput_find_field(hid, type, code, &field)) == -1) { + hid_warn(dev, "event field not found\n"); + return -1; + } + + hid_set_field(field, offset, value); + + schedule_work(&hid->led_work); + return 0; +} + static int hidinput_open(struct input_dev *dev) { struct hid_device *hid = input_get_drvdata(dev); @@ -1183,7 +1251,10 @@ static struct hid_input *hidinput_allocate(struct hid_device *hid) } input_set_drvdata(input_dev, hid); - input_dev->event = hid->ll_driver->hidinput_input_event; + if (hid->ll_driver->hidinput_input_event) + input_dev->event = hid->ll_driver->hidinput_input_event; + else if (hid->ll_driver->request || hid->hid_output_raw_report) + input_dev->event = hidinput_input_event; input_dev->open = hidinput_open; input_dev->close = hidinput_close; input_dev->setkeycode = hidinput_setkeycode; @@ -1278,6 +1349,7 @@ int hidinput_connect(struct hid_device *hid, unsigned int force) int i, j, k; INIT_LIST_HEAD(&hid->inputs); + INIT_WORK(&hid->led_work, hidinput_led_worker); if (!force) { for (i = 0; i < hid->maxcollection; i++) { @@ -1379,6 +1451,12 @@ void hidinput_disconnect(struct hid_device *hid) input_unregister_device(hidinput->input); kfree(hidinput); } + + /* led_work is spawned by input_dev callbacks, but doesn't access the + * parent input_dev at all. Once all input devices are removed, we + * know that led_work will never get restarted, so we can cancel it + * synchronously and are safe. */ + cancel_work_sync(&hid->led_work); } EXPORT_SYMBOL_GPL(hidinput_disconnect); diff --git a/include/linux/hid.h b/include/linux/hid.h index b8058c5c5594..ea4b828cb9cd 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -456,6 +456,7 @@ struct hid_device { /* device report descriptor */ enum hid_type type; /* device type (mouse, kbd, ...) */ unsigned country; /* HID country */ struct hid_report_enum report_enum[HID_REPORT_TYPES]; + struct work_struct led_work; /* delayed LED worker */ struct semaphore driver_lock; /* protects the current driver, except during input */ struct semaphore driver_input_lock; /* protects the current driver */ |