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Subject: Re: [PATCH] i2c: nvidia-gpu: Handle timeout correctly in
 gpu_i2c_check_status()
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
In-Reply-To: <20200324110930.GH1134@ninjato>
Date:   Tue, 24 Mar 2020 19:12:13 +0800
Cc:     ajayg@nvidia.com,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        "open list:I2C CONTROLLER DRIVER FOR NVIDIA GPU" 
        <linux-i2c@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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Message-Id: <9771BC92-1785-4E9A-81C7-E72C2C65CE22@canonical.com>
References: <20200311165806.12365-1-kai.heng.feng@canonical.com>
 <20200324110930.GH1134@ninjato>
To:     Wolfram Sang <wsa@the-dreams.de>
Sender: linux-kernel-owner@vger.kernel.org
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Hi Wolfram,

> On Mar 24, 2020, at 19:09, Wolfram Sang <wsa@the-dreams.de> wrote:
> 
> 
>> 	} while (time_is_after_jiffies(target));
>> 
>> -	if (time_is_before_jiffies(target)) {
>> +	if (time_is_before_eq_jiffies(target)) {
> 
> While unlikely, there is a tiny race between the time_is_* calls,
> jiffies could update inbetween them.
> 
> So, for the sake of good programming practice, I'd recommend to set a
> flag in the do_while-loop and the have the logic above solely based on
> the flag.
> 

Ok, I'll send a v2 based on your suggestion.

Kai-Heng