On 10.11.2019 04:26, Tod E. Kurt wrote: > HiI > Hi Tod, > Since you are listed as author of "hid-led.c": > https://github.com/torvalds/linux/blob/master/drivers/hid/hid-led.c, ; > I was wondering if you could offer some insight on an issue I'm seeing. > I'm a maintainer of "hidapi" and "node-hid", cross-platform C and NodeJs libraries for accessing HID devices, and I'm the creator of the ThingM blink(1) USB LED that "hid-led" controls. > > On the distros I've seen (Ubuntu, Raspian) where "hid-led" is enabled, when inserting a blink(1) device, the "hid-led" driver appears to grab the device and remove it from available "hidraw" devices. This makes generic hidraw-based systems (like "hidapi" and the upcoming Chrome WebHID) unable to see the blink(1) > > I have tried blacklisting the "hid-led" module but the problem persist. Ffrom dmesg and lsmod the module does appear to not be loaded on reboot. > > Any insights on what's going on? Any tips on how to debug this or how to prevent this from occurring? > When hid-led was written it was needed to add the LED devices to hid_have_special_driver list. Else the driver can't take control over the device. Side effect is that even if hid-led isn't loaded hid-generic can't take control. I think since e04a0442d33b ("HID: core: remove the absolute need of hid_have_special_driver[]") it's no longer needed to have the LED devices in hid_have_special_driver. Could you please test the following patch? If hid-led is loaded is should control the device, if it's blacklisted hid-generic should have the control. diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c index c50bcd967..bdaab79f7 100644 --- a/drivers/hid/hid-quirks.c +++ b/drivers/hid/hid-quirks.c @@ -419,13 +419,6 @@ static const struct hid_device_id hid_have_special_driver[] = { #if IS_ENABLED(CONFIG_HID_LCPOWER) { HID_USB_DEVICE(USB_VENDOR_ID_LCPOWER, USB_DEVICE_ID_LCPOWER_LC1000) }, #endif -#if IS_ENABLED(CONFIG_HID_LED) - { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, USB_DEVICE_ID_DREAM_CHEEKY_WN) }, - { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, USB_DEVICE_ID_DREAM_CHEEKY_FA) }, - { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_LUXAFOR) }, - { HID_USB_DEVICE(USB_VENDOR_ID_RISO_KAGAKU, USB_DEVICE_ID_RI_KA_WEBMAIL) }, - { HID_USB_DEVICE(USB_VENDOR_ID_THINGM, USB_DEVICE_ID_BLINK1) }, -#endif #if IS_ENABLED(CONFIG_HID_LENOVO) { HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_TPKBD) }, { HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_CUSBKBD) }, -- 2.24.0 > I can send you blink(1) devices and "hidapi" test programs if you'd like to try to replicate this. > Thanks for the offer, I've got a blink(1) already. Just tested the patch with this device and it worked properly like described above. > Thanks! > -=Tod Heiner
