Re: [PATCH] HID: logitech-dj: add HIDRAW dependency in Kconfig

From: Olivier Gay
Date: Tue Dec 03 2013 - 05:36:59 EST


>On Tue, Dec 3, 2013 at 8:53 AM, Jiri Kosina <jkosina@xxxxxxx> wrote:
> I don't have my receiver with me at the moment, so can't really verify --
> how exactly does it fail during probe()?

Hi Jiri,

Without hidraw driver, we get this:

<3>[ 210.131988] logitech-djreceiver 0003:046D:C52B.0005: claimed by
neither input, hiddev nor hidraw
<3>[ 210.132202] logitech-djreceiver 0003:046D:C52B.0005:
logi_dj_probe:hid_hw_start returned error

In logi_dj_probe, we call hid_hw_start with HID_CONNECT_DEFAULT
argument and if hidraw driver is not present, the call fails and we
return an error in logi_dj_probe.

> It's clear that without hidraw it's not possible to change the pairing
> from userspace, but I fail to see why probing the receiver should be
> affected?

As of today, hid-logitech-dj.c depends on hidraw API to work. All HID
reports sent to control / configure the receiver are sent using hidraw
API. That's why we fail logi_dj_probe if we cannot connect to hidraw.

Best regards,

Olivier
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