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Subject: Re: [PATCH] i2c: designware: Fix functionality in !CONFIG_ACPI case
From:   Jarkko Nikula <jarkko.nikula@linux.intel.com>
To:     John Stultz <john.stultz@linaro.org>,
        lkml <linux-kernel@vger.kernel.org>
Cc:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Wolfram Sang <wsa@kernel.org>, linux-i2c@vger.kernel.org
References: <20200623025144.34246-1-john.stultz@linaro.org>
 <d6c317ee-4f97-9c57-6b04-1eabd814b6ce@linux.intel.com>
Message-ID: <96ea5e42-0632-4c8b-03c2-4958b9eea8c5@linux.intel.com>
Date:   Tue, 23 Jun 2020 11:33:30 +0300
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On 6/23/20 10:59 AM, Jarkko Nikula wrote:
> Hi
> 
> On 6/23/20 5:51 AM, John Stultz wrote:
>> On the HiKey board, where CONFIG_ACPI is not set, we started
>> to see a graphics regression where the adv7511 HDMI bridge driver
>> wasn't probing. This was due to the i2c bus failing to start up.
>>
>> I bisected the problem down to commit f9288fcc5c615 ("i2c:
>> designware: Move ACPI parts into common module") and after
>> looking at it a bit, I realized that change moved some
>> initialization into i2c_dw_acpi_adjust_bus_speed(). However,
>> i2c_dw_acpi_adjust_bus_speed() is only functional if CONFIG_ACPI
>> is set.
>>
>> This patch pulls i2c_dw_acpi_adjust_bus_speed() out of the
>> ifdef CONFIG_ACPI conditional, and gets the board working again.
>>
> Andy: what you think should the i2c_dw_acpi_adjust_bus_speed() fixed to 
> return adjusted speed or zero if not found (also for !CONFIG_ACPI) and 
> move above lines back to probe? It looks more clear to me that way and 
> should fix the regression I think.
> 
Ok, I sent a patch what I was thinking. Care to test John does it fix 
the regression you are seeing?

-- 
Jarkko