Message-ID: <1416515255.25223.1.camel@linux-0dmf.site>
Subject: Re: [PATCH v1] Input: elants_i2c: Add Elan touchscreen support
From: Oliver Neukum <oneukum@suse.de>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: scott <scott.liu@emc.com.tw>, linux-kernel@vger.kernel.org,
        linux-input@vger.kernel.org, Vincent Wang <vincent.wang@emc.com.tw>,
        Jeff Chuang <jeff.chuang@emc.com.tw>,
        Benson Leung <bleung@chromium.org>,
        Benjamin Tissoires <benjamin.tissoires@gmail.com>,
        Henrik Rydberg <rydberg@euromail.se>,
        David Herrmann <dh.herrmann@gmail.com>
Date: Thu, 20 Nov 2014 21:27:35 +0100
In-Reply-To: <20141120174709.GA14798@dtor-glaptop>
References: <1388146515-19481-1-git-send-email-scott.liu@emc.com.tw>
	 <20141120081113.GA37534@dtor-ws>
	 <1416479490.28599.13.camel@linux-0dmf.site>
	 <20141120174709.GA14798@dtor-glaptop>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

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.

	Regards
		Oliver


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/