On 06/09/2015 07:42 PM, Dmitry Torokhov wrote:

From: Samuel Thibault <samuel.thibault@ens-lyon.org>

This change creates a new input handler called "leds" that exports LEDs on input
devices as standard LED class devices in sysfs and allows controlling their
ptate via sysfs or via any of the standard LED triggers. This allows to
re-purpose and reassign LDEs on the keyboards to represent states other
than the standard keyboard states (CapsLock, NumLock, etc).

The old API of controlling input LEDs by writing into /dev/input/eventX
devices is still present and will take precedence over acessing via LEDs
subsystem (i.e. it may override state set by a trigger). If input device is
"grabbed" then requests coming through LED subsystem will be ignored.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

+	led_no = 0;
+	for_each_set_bit(led_code, dev->ledbit, LED_CNT) {
+		struct input_led *led = &leds->leds[led_no];
+
+		led->handle = &leds->handle;
+		led->code = led_code;
+
+		if (WARN_ON(!input_led_info[led_code].name))
+			continue;
+

Hi,
I get several warnings on booting 4.2-rc2 here. Should I be worried?

[    2.782432] ------------[ cut here ]------------
[    2.782440] WARNING: CPU: 2 PID: 356 at ../drivers/input/input-leds.c:115 input_leds_connect+0x22b/0x260()
[    2.782441] Modules linked in: btrfs xor raid6_pq crc32c_intel radeon i2c_algo_bit sr_mod cdrom drm_kms_helper ttm e1000e drm xhci_pci ptp pps_core xhci_hcd sg
[    2.782453] CPU: 2 PID: 356 Comm: kworker/2:2 Not tainted 4.2.0-rc2-1.g288d56b-desktop #1
[    2.782454] Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A13 03/27/2013
[    2.782458] Workqueue: usb_hub_wq hub_event
[    2.782459]  ffffffff81a917b7 ffff880213ecf298 ffffffff8169f19d 0000000000000007
[    2.782462]  0000000000000000 ffff880213ecf2d8 ffffffff810674f6 ffff880213ecf2f8
[    2.782463]  ffff8802132fb000 0000000000000003 000000000000000b ffff8800369ff000
[    2.782465] Call Trace:
[    2.782470]  [<ffffffff8169f19d>] dump_stack+0x4c/0x6e
[    2.782474]  [<ffffffff810674f6>] warn_slowpath_common+0x86/0xc0
[    2.782476]  [<ffffffff810675ea>] warn_slowpath_null+0x1a/0x20
[    2.782478]  [<ffffffff8152ccdb>] input_leds_connect+0x22b/0x260
[    2.782480]  [<ffffffff815281b2>] input_attach_handler+0x1a2/0x1f0
[    2.782483]  [<ffffffff81528640>] input_register_device+0x440/0x4f0
[    2.782486]  [<ffffffff8156e494>] hidinput_connect+0x334/0x5d0
[    2.782488]  [<ffffffff815683d4>] hid_connect+0x324/0x400
[    2.782490]  [<ffffffff81578b7a>] ? usbhid_start+0x54a/0x780
[    2.782492]  [<ffffffff81569858>] hid_device_probe+0x118/0x140
[    2.782495]  [<ffffffff81482134>] driver_probe_device+0x1f4/0x460
[    2.782497]  [<ffffffff814824b9>] __device_attach_driver+0x79/0xa0
[    2.782499]  [<ffffffff81482440>] ? __driver_attach+0xa0/0xa0
[    2.782501]  [<ffffffff8147ff6b>] bus_for_each_drv+0x5b/0x90
[    2.782502]  [<ffffffff81481e58>] __device_attach+0xa8/0x120
[    2.782504]  [<ffffffff81482523>] device_initial_probe+0x13/0x20
[    2.782506]  [<ffffffff8148116a>] bus_probe_device+0x9a/0xb0
[    2.782508]  [<ffffffff8147edee>] device_add+0x3fe/0x670
[    2.782511]  [<ffffffff812bf9d3>] ? debugfs_create_file+0xd3/0x110
[    2.782513]  [<ffffffff8156956c>] hid_add_device+0xcc/0x2a0
[    2.782515]  [<ffffffff81578404>] usbhid_probe+0x2e4/0x410
[    2.782518]  [<ffffffff814fe0d2>] usb_probe_interface+0x1b2/0x2d0
[    2.782519]  [<ffffffff81482134>] driver_probe_device+0x1f4/0x460
[    2.782521]  [<ffffffff814824b9>] __device_attach_driver+0x79/0xa0
[    2.782523]  [<ffffffff81482440>] ? __driver_attach+0xa0/0xa0
[    2.782525]  [<ffffffff8147ff6b>] bus_for_each_drv+0x5b/0x90
[    2.782526]  [<ffffffff81481e58>] __device_attach+0xa8/0x120
[    2.782528]  [<ffffffff81482523>] device_initial_probe+0x13/0x20
[    2.782530]  [<ffffffff8148116a>] bus_probe_device+0x9a/0xb0
[    2.782531]  [<ffffffff8147edee>] device_add+0x3fe/0x670
[    2.782533]  [<ffffffff814fbfb1>] usb_set_configuration+0x501/0x8e0
[    2.782535]  [<ffffffff81253efe>] ? kernfs_add_one+0xee/0x140
[    2.782537]  [<ffffffff8150656e>] generic_probe+0x2e/0x80
[    2.782539]  [<ffffffff814fdee2>] usb_probe_device+0x32/0x70
[    2.782541]  [<ffffffff81482134>] driver_probe_device+0x1f4/0x460
[    2.782542]  [<ffffffff814824b9>] __device_attach_driver+0x79/0xa0
[    2.782544]  [<ffffffff81482440>] ? __driver_attach+0xa0/0xa0
[    2.782546]  [<ffffffff8147ff6b>] bus_for_each_drv+0x5b/0x90
[    2.782547]  [<ffffffff81481e58>] __device_attach+0xa8/0x120
[    2.782549]  [<ffffffff81482523>] device_initial_probe+0x13/0x20
[    2.782551]  [<ffffffff8148116a>] bus_probe_device+0x9a/0xb0
[    2.782552]  [<ffffffff8147edee>] device_add+0x3fe/0x670
[    2.782554]  [<ffffffff814f15c6>] ? usb_new_device+0x216/0x5d0
[    2.782556]  [<ffffffff814f164e>] usb_new_device+0x29e/0x5d0
[    2.782559]  [<ffffffff8148cff1>] ? pm_runtime_set_autosuspend_delay+0x51/0x60
[    2.782561]  [<ffffffff81506612>] ? __usb_detect_quirks+0x52/0x110
[    2.782563]  [<ffffffff814f2c3f>] hub_port_connect+0x31f/0x9c0
[    2.782565]  [<ffffffff814f39b1>] hub_event+0x6d1/0xb10
[    2.782568]  [<ffffffff8107f039>] process_one_work+0x159/0x470
[    2.782570]  [<ffffffff8107f398>] worker_thread+0x48/0x4a0
[    2.782572]  [<ffffffff8107f350>] ? process_one_work+0x470/0x470
[    2.782574]  [<ffffffff8107f350>] ? process_one_work+0x470/0x470
[    2.782576]  [<ffffffff81085089>] kthread+0xc9/0xe0
[    2.782579]  [<ffffffff81084fc0>] ? kthread_worker_fn+0x170/0x170
[    2.782581]  [<ffffffff816a55df>] ret_from_fork+0x3f/0x70
[    2.782583]  [<ffffffff81084fc0>] ? kthread_worker_fn+0x170/0x170
[    2.782585] ---[ end trace ce1cb4ca0f2cbd0b ]---
[    2.782586] ------------[ cut here ]------------