On 10.11.2019 17:59, Tod E. Kurt wrote: > Hi Heiner, (and others on the list) > > Thanks for your quick and detailed response. > > I am endeavoring to try the patch out now. But I've not built a desktop Linux kernel or kernel modules in about 15 years. Do you have a preferred recipe for applying this patch to an existing distro? Since 'hid-quirks' isn't a module, this means recompiling the entire HID driver, correct? I mostly test against various modern Ubuntu or Raspian flavors of Debian, if that matters. > See e.g. here: https://wiki.ubuntu.com/Kernel/BuildYourOwnKernel > Also, is there a mitigation for users running production distros that doesn't involve a recompile? > I don't think so (at least from kernel perspective). What you could do is adding an integration with the /sys/class/led interface in your library (if it should be suitable for your use cases) and auto-detect which interface to use. > Thanks, > -=Tod > Heiner >> On Nov 10, 2019, at 2:44 a, Heiner Kallweit <hkallweit1@xxxxxxxxx> wrote: >> >> 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 > >
