Re: [PATCH v1] Input: elants_i2c: Add Elan touchscreen support

From: Dmitry Torokhov
Date: Thu Nov 20 2014 - 15:35:32 EST


On Thu, Nov 20, 2014 at 09:27:35PM +0100, Oliver Neukum wrote:
> On Thu, 2014-11-20 at 09:47 -0800, Dmitry Torokhov wrote:
> > Hi Oliver,
> >
> > On Thu, Nov 20, 2014 at 11:31:30AM +0100, Oliver Neukum wrote:
> > > > +static int elants_i2c_initialize(struct elants_data *ts)
> > > > +{
> > > > + struct i2c_client *client = ts->client;
> > > > + int error, retry_cnt;
> > > > + const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
> > > > + const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
> > > > + u8 buf[HEADER_SIZE];
> > > > +
> > >
> > > Strictly speaking you should disable preemption here.
> >
> > Umm, why?
>
> You said the upper bound matters. So you need to protect yourself
> against losing too much time by preemption.

We are using i2c so we can't really disable preemption here... I think
we have enough slack, although I would indeed lower the sleep time.
I'll let Scott comment on that.

Thanks.

--
Dmitry
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