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Message-ID: <1444053984.8404.1.camel@redhat.com>
Subject: Re: [PATCH v6.1 1/1] Input: Add userio module
From: Stephen Chandler Paul <cpaul@redhat.com>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: David Herrmann <dh.herrmann@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-input@vger.kernel.org, linux-api@vger.kernel.org,
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        Greg KH <gregkh@linuxfoundation.org>, Arnd Bergmann <arnd@arndb.de>,
        Joe Perches <joe@perches.com>, Jiri Slaby <jslaby@suse.com>,
        Vishnu Patekar <vishnupatekar0510@gmail.com>,
        Sebastian Ott <sebott@linux.vnet.ibm.com>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        Hans de Goede <hdegoede@redhat.com>, linux-doc@vger.kernel.org
Date: Mon, 05 Oct 2015 10:06:24 -0400
In-Reply-To: <20151002173714.GA8437@dtor-ws>
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On Fri, 2015-10-02 at 10:37 -0700, Dmitry Torokhov wrote:
> On Wed, Sep 23, 2015 at 01:54:59PM -0400, cpaul@redhat.com wrote:
> > +static int userio_device_write(struct serio *id, unsigned char
> > val)
> > +{
> > +	struct userio_device *userio = id->port_data;
> > +	unsigned long flags;
> > +
> > +	if (!userio)
> > +		return -1;
> 
> I still have the same question: how can this happen? Where do we
> reset
> port data to NULL? What happens if we set to NULL after checking?
> 

Actually David pointed out this line was not needed, somehow it still
got left in the patch. I'll send an updated version in just a minute
with the changes.

Cheers,
	Lyude
> > +
> > +	spin_lock_irqsave(&userio->buf_lock, flags);
> > +
> > +	userio->buf[userio->head] = val;
> > +	userio->head = (userio->head + 1) % USERIO_BUFSIZE;
> > +
> > +	if (userio->head == userio->tail)
> > +		dev_warn(userio_misc.this_device,
> > +			 "Buffer overflowed, userio client isn't
> > keeping up");
> > +
> > +	spin_unlock_irqrestore(&userio->buf_lock, flags);
> > +
> > +	wake_up_interruptible(&userio->waitq);
> > +
> > +	return 0;
> > +}
> 
> Thanks.
>