diff mbox

[v2,1/3] Input: export LEDs as class devices in sysfs

Message ID alpine.LNX.2.00.1507222145030.1141@pobox.suse.cz (mailing list archive)
State New, archived
Headers show

Commit Message

Jiri Kosina July 22, 2015, 7:49 p.m. UTC 
On Wed, 22 Jul 2015, Vlastimil Babka wrote:

> [  101.805120] usb 3-4: new low-speed USB device number 3 using xhci_hcd
> [  101.979584] usb 3-4: New USB device found, idVendor=046d, idProduct=c50e
> [  101.979589] usb 3-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> [  101.979592] usb 3-4: Product: USB Receiver
> [  101.979594] usb 3-4: Manufacturer: Logitech
> [  101.979805] usb 3-4: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes
> [  101.989010] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989014] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989017] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989019] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989021] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989023] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989025] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989027] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> [  101.989091] input: Logitech USB Receiver as /devices/pci0000:00/0000:00:14.0/usb3/3-4/3-4:1.0/0003:046D:C50E.0003/input/input14
> [  102.039320] ------------[ cut here ]------------
> [  102.039329] WARNING: CPU: 6 PID: 168 at ../drivers/input/input-leds.c:115 input_leds_connect+0x22b/0x260()
> 
> (5 WARNINGs as before)
> 
> [  102.040729] hid-generic 0003:046D:C50E.0003: input,hidraw2: USB HID v1.11 Mouse [Logitech USB Receiver] on usb-0000:00:14.0-4/input0

Alright, I think it's pretty obvious what's happening. Vlastimil, am I 
right that the patch below fixes the issue?

I am however not sure whether input_leds_connect() is not too unkind to 
unnamed LEDs and shouldn't be more tolerant to those in the long term.





From: Jiri Kosina <jkosina@suse.com>
Subject: [PATCH] Input: leds: don't attempt to deregister unnamed LEDs

input_leds_connect() is skipping registration of LEDs for which
there is no symbolic name in input_led_info[].

The way how usages are mapped in hidinput_configure_usage() directly
implies that this will trigger also when there are duplicate mappings
of LEDs (as only the first one will be mapped accordingly to the descriptor,
and the remaining ones will be mapped to first free bits in the ledbit
bitfield).

We are however not skipping such mappings when deregistering, which
causes memory corruption.

Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
---
 drivers/input/input-leds.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Dmitry Torokhov July 22, 2015, 9:49 p.m. UTC | #1 
On Wed, Jul 22, 2015 at 09:49:06PM +0200, Jiri Kosina wrote:
> On Wed, 22 Jul 2015, Vlastimil Babka wrote:
> 
> > [  101.805120] usb 3-4: new low-speed USB device number 3 using xhci_hcd
> > [  101.979584] usb 3-4: New USB device found, idVendor=046d, idProduct=c50e
> > [  101.979589] usb 3-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> > [  101.979592] usb 3-4: Product: USB Receiver
> > [  101.979594] usb 3-4: Manufacturer: Logitech
> > [  101.979805] usb 3-4: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes
> > [  101.989010] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989014] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989017] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989019] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989021] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989023] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989025] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989027] hid-generic 0003:046D:C50E.0003: Mapped LED usage 4b as LED 8
> > [  101.989091] input: Logitech USB Receiver as /devices/pci0000:00/0000:00:14.0/usb3/3-4/3-4:1.0/0003:046D:C50E.0003/input/input14
> > [  102.039320] ------------[ cut here ]------------
> > [  102.039329] WARNING: CPU: 6 PID: 168 at ../drivers/input/input-leds.c:115 input_leds_connect+0x22b/0x260()
> > 
> > (5 WARNINGs as before)
> > 
> > [  102.040729] hid-generic 0003:046D:C50E.0003: input,hidraw2: USB HID v1.11 Mouse [Logitech USB Receiver] on usb-0000:00:14.0-4/input0
> 
> Alright, I think it's pretty obvious what's happening. Vlastimil, am I 
> right that the patch below fixes the issue?
> 
> I am however not sure whether input_leds_connect() is not too unkind to 
> unnamed LEDs and shouldn't be more tolerant to those in the long term.

Yes, I'll change how we count the leds to skip unnamed, then the patch
below won't be needed.

BTW, maybe we should be using hid_map_usage_clear() in map_led() as it
does not make much sense to convert CAPS LOCK into SCROLL LOCK in case
keyboard happens to have 2 usages for caps...

Thanks.
Jiri Kosina July 22, 2015, 10:01 p.m. UTC | #2 
On Wed, 22 Jul 2015, Dmitry Torokhov wrote:

> Yes, I'll change how we count the leds to skip unnamed, then the patch
> below won't be needed.

Agreed.

> BTW, maybe we should be using hid_map_usage_clear() in map_led() as it 
> does not make much sense to convert CAPS LOCK into SCROLL LOCK in case 
> keyboard happens to have 2 usages for caps...

Indeed, makes sense generally for all LEDs I think.
diff mbox

Patch

diff --git a/drivers/input/input-leds.c b/drivers/input/input-leds.c
index 074a65e..3be81ac 100644
--- a/drivers/input/input-leds.c
+++ b/drivers/input/input-leds.c
@@ -145,6 +145,10 @@  err_unregister_leds:
 	while (--led_no >= 0) {
 		struct input_led *led = &leds->leds[led_no];
 
+		/* Unnamed LEDs are not registered with led class */
+		if (!input_led_info[led->code].name)
+			continue;
+
 		led_classdev_unregister(&led->cdev);
 		kfree(led->cdev.name);
 	}