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Subject: Re: [PATCH 4/6] i2c: designware: Detect the FIFO size in the common
 code
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Sergey.Semin@baikalelectronics.ru
Cc:     Mika Westerberg <mika.westerberg@linux.intel.com>,
        Serge Semin <fancer.lancer@gmail.com>,
        Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Paul Burton <paulburton@kernel.org>,
        Ralf Baechle <ralf@linux-mips.org>, linux-i2c@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20200306131955.12806-1-Sergey.Semin@baikalelectronics.ru>
 <20200306132151.2ABC38030786@mail.baikalelectronics.ru>
 <20200306150138.GN1748204@smile.fi.intel.com>
From:   Jarkko Nikula <jarkko.nikula@linux.intel.com>
Message-ID: <c119e638-0fd5-8ad0-be7f-ac408e62e66f@linux.intel.com>
Date:   Thu, 12 Mar 2020 16:50:07 +0200
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On 3/6/20 5:01 PM, Andy Shevchenko wrote:
> On Fri, Mar 06, 2020 at 04:19:54PM +0300, Sergey.Semin@baikalelectronics.ru wrote:
>> From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
>>
>> The problem with detecting the FIFO depth in the platform driver
>> is that in order to implement this we have to access the controller
>> IC_COMP_PARAM_1 register. Currently it's done before the
>> i2c_dw_set_reg_access() method execution, which is errors prone since
>> the method determines the registers endianness and access mode and we
>> can't use dw_readl/dw_writel accessors before this information is
>> retrieved. We also can't move the i2c_dw_set_reg_access() function
>> invocation to after the master/slave probe functions call (when endianness
>> and access mode are determined), since the FIFO depth information is used
>> by them for initializations. So in order to fix the problem we have no
>> choice but to move the FIFO size detection methods to the common code and
>> call it at the probe stage.
> 
> Sounds reasonable.
> 
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>