Message-ID: <54368AA2.9000104@opensource.altera.com>
Date: Thu, 9 Oct 2014 08:16:18 -0500
From: Dinh Nguyen <dinguyen@opensource.altera.com>
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To: Philipp Zabel <p.zabel@pengutronix.de>
CC: <dinh.linux@gmail.com>, <s.trumtrar@pengutronix.de>,
        <grant.likely@linaro.org>, <robh+dt@kernel.org>,
        <atull@opensource.altera.com>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] reset: socfpga: use arch_initcall for early initialization
References: <1412822646-11257-1-git-send-email-dinguyen@opensource.altera.com> <1412845410.6809.3.camel@pengutronix.de>
In-Reply-To: <1412845410.6809.3.camel@pengutronix.de>
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Hi Philipp,

On 10/9/14, 4:03 AM, Philipp Zabel wrote:
> Am Mittwoch, den 08.10.2014, 21:44 -0500 schrieb
> dinguyen@opensource.altera.com:
>> From: Dinh Nguyen <dinguyen@opensource.altera.com>
>>
>> There are certain drivers that are required to get loaded very early using
>> arch_initcall. An example of such a driver is the SOCFPGA's FPGA bridge driver.
>> This driver has to get loaded early because it needs to enable FPGA components
>> that are connected to the bridge.
>>
>> This FPGA bridge driver will using the reset controller API to toggle it's
>> reset bits, thus, it needs the reset driver to be loaded as early as possible
>> in order for it to get used properly.
> 
> Without knowing the details, this sounds like the wrong approach. Can't
> the bridge driver return -EPROBE_DEFER until the reset controller is
> available?
> 

The bridge driver is also using arch_initcall, as it also needs to get
loaded early for FPGA IPs to work, and so later driver loading will work
for the FPGA IPs.

Dinh
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