Re: [PATCH] HID: hid-input: avoid splitting keyboard, system and consumer controls
On Wed, 13 Jan 2021, Dmitry Torokhov wrote: > A typical USB keyboard usually splits its keys into several reports: > > - one for the basic alphanumeric keys, modifier keys, F keys, six pack > keys and keypad. This report's application is normally listed as > GenericDesktop.Keyboard > - a GenericDesktop.SystemControl report for the system control keys, such > as power and sleep > - Consumer.ConsumerControl report for multimedia (forward, rewind, > play/pause, mute, etc) and other extended keys. > - additional output, vendor specific, and feature reports > > Splitting each report into a separate input device is wasteful and even > hurts userspace as it makes it harder to determine the true capabilities > (set of available keys) of a keyboard, so let's adjust application > matching to merge system control and consumer control reports with > keyboard report, if one has already been processed. > > Signed-off-by: Dmitry Torokhov > --- Queued in for-5.12/core. Thanks, -- Jiri Kosina SUSE Labs
Re: [PATCH] HID: hid-input: avoid splitting keyboard, system and consumer controls
On Wed, Jan 13, 2021 at 10:24:13PM -0800, Dmitry Torokhov wrote: > A typical USB keyboard usually splits its keys into several reports: > > - one for the basic alphanumeric keys, modifier keys, F keys, six pack > keys and keypad. This report's application is normally listed as > GenericDesktop.Keyboard > - a GenericDesktop.SystemControl report for the system control keys, such > as power and sleep > - Consumer.ConsumerControl report for multimedia (forward, rewind, > play/pause, mute, etc) and other extended keys. > - additional output, vendor specific, and feature reports > > Splitting each report into a separate input device is wasteful and even > hurts userspace as it makes it harder to determine the true capabilities > (set of available keys) of a keyboard, so let's adjust application > matching to merge system control and consumer control reports with > keyboard report, if one has already been processed. > > Signed-off-by: Dmitry Torokhov Acked-by: Peter Hutterer I think, let's see if there's any fallout from that :) Cheers, Peter
Re: [PATCH] HID: hid-input: avoid splitting keyboard, system and consumer controls
Hi Benjamin,
On Thu, Jan 14, 2021 at 10:23:02AM +0100, Benjamin Tissoires wrote:
> Hi Dmitry,
>
> On Thu, Jan 14, 2021 at 7:24 AM Dmitry Torokhov
> wrote:
> >
> > A typical USB keyboard usually splits its keys into several reports:
> >
> > - one for the basic alphanumeric keys, modifier keys, F keys, six pack
> > keys and keypad. This report's application is normally listed as
> > GenericDesktop.Keyboard
> > - a GenericDesktop.SystemControl report for the system control keys, such
> > as power and sleep
> > - Consumer.ConsumerControl report for multimedia (forward, rewind,
> > play/pause, mute, etc) and other extended keys.
> > - additional output, vendor specific, and feature reports
> >
> > Splitting each report into a separate input device is wasteful and even
> > hurts userspace as it makes it harder to determine the true capabilities
> > (set of available keys) of a keyboard, so let's adjust application
> > matching to merge system control and consumer control reports with
> > keyboard report, if one has already been processed.
> >
> > Signed-off-by: Dmitry Torokhov
> > ---
> > drivers/hid/hid-input.c | 10 ++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> > index f797659cb9d9..df45d8d07dc2 100644
> > --- a/drivers/hid/hid-input.c
> > +++ b/drivers/hid/hid-input.c
> > @@ -1851,6 +1851,16 @@ static struct hid_input
> > *hidinput_match_application(struct hid_report *report)
> > list_for_each_entry(hidinput, >inputs, list) {
> > if (hidinput->application == report->application)
> > return hidinput;
> > +
> > + /*
> > +* Keep SystemControl and ConsumerControl applications
> > together
> > +* with the main keyboard, if present.
> > +*/
> > + if ((report->application == HID_GD_SYSTEM_CONTROL ||
> > +report->application == HID_CP_CONSUMER_CONTROL) &&
> > + hidinput->application == HID_GD_KEYBOARD) {
>
> I am not fundamentally against the patch, but I think that if the
> device exposes first a HID_CP_CONSUMER_CONTROL and then a
> HID_GD_KEYBOARD we will end up with 2 different input nodes. We likely
> need to "convert" HID_GD_SYSTEM_CONTROL and HID_CP_CONSUMER_CONTROL to
> HID_GD_KEYBOARD when creating the hidinput.
While it is technically possible that consumer control or system control
comes first, before main keyboard report, in reality all keyboards that
I have seen so far have the main keyboard report first, so I opted not
to handle the uncommon case to keep the code simple.
I could add the above as a comment, and we could wait to see if there
are devices that are exceptions to the common practice, or I can go and
try to implement the conversion if you feel it is required. Please let
me know.
Note that we will still end up with 2+ input nodes if a device uses
several USB interfaces, but we can't really do much about such cases
(well, short of having a specialized driver claiming additional
interfaces while probing the first one, but that is really outside of
scope of this patch).
Thanks!
--
Dmitry
Re: [PATCH] HID: hid-input: avoid splitting keyboard, system and consumer controls
Hi Dmitry,
On Thu, Jan 14, 2021 at 7:24 AM Dmitry Torokhov
wrote:
>
> A typical USB keyboard usually splits its keys into several reports:
>
> - one for the basic alphanumeric keys, modifier keys, F keys, six pack
> keys and keypad. This report's application is normally listed as
> GenericDesktop.Keyboard
> - a GenericDesktop.SystemControl report for the system control keys, such
> as power and sleep
> - Consumer.ConsumerControl report for multimedia (forward, rewind,
> play/pause, mute, etc) and other extended keys.
> - additional output, vendor specific, and feature reports
>
> Splitting each report into a separate input device is wasteful and even
> hurts userspace as it makes it harder to determine the true capabilities
> (set of available keys) of a keyboard, so let's adjust application
> matching to merge system control and consumer control reports with
> keyboard report, if one has already been processed.
>
> Signed-off-by: Dmitry Torokhov
> ---
> drivers/hid/hid-input.c | 10 ++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> index f797659cb9d9..df45d8d07dc2 100644
> --- a/drivers/hid/hid-input.c
> +++ b/drivers/hid/hid-input.c
> @@ -1851,6 +1851,16 @@ static struct hid_input
> *hidinput_match_application(struct hid_report *report)
> list_for_each_entry(hidinput, >inputs, list) {
> if (hidinput->application == report->application)
> return hidinput;
> +
> + /*
> +* Keep SystemControl and ConsumerControl applications
> together
> +* with the main keyboard, if present.
> +*/
> + if ((report->application == HID_GD_SYSTEM_CONTROL ||
> +report->application == HID_CP_CONSUMER_CONTROL) &&
> + hidinput->application == HID_GD_KEYBOARD) {
I am not fundamentally against the patch, but I think that if the
device exposes first a HID_CP_CONSUMER_CONTROL and then a
HID_GD_KEYBOARD we will end up with 2 different input nodes. We likely
need to "convert" HID_GD_SYSTEM_CONTROL and HID_CP_CONSUMER_CONTROL to
HID_GD_KEYBOARD when creating the hidinput.
Cheers,
Benjamin
> + return hidinput;
> + }
> }
>
> return NULL;
> --
> 2.30.0.284.gd98b1dd5eaa7-goog
>
>
> --
> Dmitry
>
