From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: "Vojtěch Boček" <vbocek@gmail.com>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] Input: joydev - fix axes values sent in initial js_event
Date: Wed, 12 Sep 2012 21:52:06 -0700 [thread overview]
Message-ID: <20120913045206.GB17105@core.coreip.homeip.net> (raw)
In-Reply-To: <CAOeGmboLCan-fX4sPPxS5jkyepxLTSnRgvdHJ0-edcH8UCQg+w@mail.gmail.com>
On Wed, Sep 05, 2012 at 10:09:57PM +0200, Vojtěch Boček wrote:
> Hi,
>
> 2012/9/5 Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > So what guarantees that joystick events will arrive in time, before
> > joydev_generate_startup_event() is called? It looks like your solution
> > is racy...
> >
> > I wonder if we should not generate the startup event until we have seen
> > at least one EV_SYN, i.e. entire device state has been transmitted to
> > us.
>
> I just tried to delay read() until first EV_SYN arrives as you suggested,
> but that was not the problem, at least not the main one. First joystick
> input events arrives immediately after it is plugged in and driver is loaded,
> but when that happens, joydev may not be (and most likely is not)
> opened yet, which means the events will never reach joydev because of
> "if (!handle->open)" check in input_pass_event.
>
> I wonder how to handle this. Is "if(!handle->open)" valid check? I think so,
> my guess is that joydev is the only handler with internal buffer, and it
> is useless to update that buffer when the device is not opened.
> I think reloading abs values on joydev open should be okay.
>
> I suppose that if we reload abs values on joydev open, waiting for first
> sync is not needed, yes?
>
> So the patch could look like this:
This makes sense. Just to confirm - have you tried the patch and
verified it works for you?
Thanks.
--
Dmitry
next prev parent reply other threads:[~2012-09-13 4:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-13 22:11 [PATCH 1/1] Input: joydev - fix axes values sent in initial js_event Vojtech Bocek
2012-09-05 5:52 ` Dmitry Torokhov
2012-09-05 20:09 ` Vojtěch Boček
2012-09-13 4:52 ` Dmitry Torokhov [this message]
2012-09-13 10:55 ` Vojtech Bocek
2012-11-01 16:47 ` Vojtech Bocek
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