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Date: Fri, 12 Jul 2013 10:53:51 +0530
From: Kishon Vijay Abraham I <kishon@ti.com>
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To: Jingoo Han <jg1.han@samsung.com>
CC: "'Bjorn Helgaas'" <bhelgaas@google.com>,
	<linux-pci@vger.kernel.org>, <linux-samsung-soc@vger.kernel.org>,
	"'Kukjin Kim'" <kgene.kim@samsung.com>,
	"'Pratyush Anand'" <pratyush.anand@st.com>,
	"'Mohit KUMAR'" <Mohit.KUMAR@st.com>,
	"'Arnd Bergmann'" <arnd@arndb.de>,
	"'Sean Cross'" <xobs@kosagi.com>,
	"'SRIKANTH TUMKUR SHIVANAND'" <ts.srikanth@samsung.com>,
	<linux-kernel@vger.kernel.org>,
	"'Thierry Reding'" <thierry.reding@gmail.com>
Subject: Re: [PATCH V2] pci: exynos: split into two parts such as Synopsys
 part and Exynos part
References: <001201ce7dfa$716b3370$54419a50$@samsung.com> <51DE72CC.9050001@ti.com> <001301ce7e92$d19a04e0$74ce0ea0$@samsung.com>
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On Friday 12 July 2013 05:30 AM, Jingoo Han wrote:
> On Thursday, July 11, 2013 5:55 PM, Kishon Vijay Abraham I wrote:
>> On Thursday 11 July 2013 11:19 AM, Jingoo Han wrote:
>>> Exynos PCIe IP consists of Synopsys specific part and Exynos
>>> specific part. Only core block is a Synopsys designware part;
>>> other parts are Exynos specific.
>>> Also, the Synopsys designware part can be shared with other
>>> platforms; thus, it can be split two parts such as Synopsys
>>> designware part and Exynos specific part.
>>>
>>> Signed-off-by: Jingoo Han <jg1.han@samsung.com>
>>> Cc: Pratyush Anand <pratyush.anand@st.com>
>>> Cc: Mohit KUMAR <Mohit.KUMAR@st.com>
>>> ---
>> .
>> .
>> <snip>
>> .
>> .
>>> +
>>> +/* Exynos PCIe driver does not allow module unload */
>>
>> Just curious, why is this restriction?
> 
> CC'ed Thierry Reding,
> 
> Hi Kishon,
> 
> That's a good question.
> 
> Now, we don't have the solution to "be able to load and unload
> the PCI host driver in a loop definitely without crashing or exposing
> any races  or leaks", as Arnd Bergmann said.
> Please refer to the following thread in mailing-list.
> (http://archive.arm.linux.org.uk/lurker/message/20130614.123849.4ff363c5.pl.html)

That explains.

Thanks
Kishon