linux-kernel - Re: Re: [PATCH v2] i2c: cadence: try reset when master receive arbitration lost

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Message-ID: <2019110516474778997625@163.com>
Date:   Tue, 5 Nov 2019 16:47:53 +0800
From:   "sxauwsk@....com" <sxauwsk@....com>
To:     "Shubhrajyoti Datta" <shubhrajyoti.datta@...il.com>
Cc:     "Michal Simek" <michal.simek@...inx.com>,
        "Shubhrajyoti Datta" <shubhrajyoti.datta@...inx.com>,
        "Wolfram Sang" <wsa@...-dreams.de>,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
        linux-i2c <linux-i2c@...r.kernel.org>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: Re: [PATCH v2] i2c: cadence: try reset when master receive arbitration lost

>Hi Shikai,
>
>On Tue, Feb 19, 2019 at 8:19 AM Shikai Wang <sxauwsk@....com> wrote:
>>
>> When the adapter receive arbitration lost error interrupts,
>> cdns_i2c_master_xfer return to the caller directly instead of resetting
>> the adapter which resulted in the adapter being out of control.
>>
>> So when driver detect err_status such as arbitration lost,
>> then try to repair and fix it.
>>
>I am missing the issue that you are facing.
>You are having a multimaster scenario and getting arbitration lost.
>
>the current code would attempt a retry did that lead to any issues?
>
>Can you explain the issue that you are facing? 

Of cource,  The following describe my situation.

In my product,  Touchscreen connect to zynq-7000 XC7Z010 by i2c bus( Just connect only one i2c-device of touchscreen),  
when user tap Touchscreen, Touchscreen interrupt send to CPU and notifyed i2c-driver to obtain location data by i2c-bus,  

when Tap the screen frequently,  sometimes CPU get interrupt from touchscreen and try to obtain data,  then detect arbitration lost,
Although i2c-driver try three times,  it's useless.
  
Actually i2c clock-line and data-line keep high, that mean i2c bus free.
Once this situation occur, i2c-control did't work anynay but cpu receive interrputs still.

I am sorry that I have't found a good solution for this issuse;