Re: [PATCH v6.1 1/1] Input: Add userio module

From: Stephen Chandler Paul
Date: Mon Oct 05 2015 - 10:06:33 EST


On Fri, 2015-10-02 at 10:37 -0700, Dmitry Torokhov wrote:
> On Wed, Sep 23, 2015 at 01:54:59PM -0400, cpaul@xxxxxxxxxx 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.
>
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