From mboxrd@z Thu Jan  1 00:00:00 1970
From: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Subject: Re: [PATCH] serial: Skip over PCIe device which have no
 quirks (fix AMT regression).
Date: Thu, 6 Mar 2014 15:33:03 -0600
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To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: "Lendacky, Thomas" <Thomas.Lendacky@amd.com>, Keir Fraser <keir@xen.org>, Jan Beulich <jbeulich@suse.com>, Konrad Rzeszutek Wilk <konrad@kernel.org>, "Suthikulpanit,
	Suravee" <Suravee.Suthikulpanit@amd.com>, "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
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On 3/5/2014 6:43 PM, Konrad Rzeszutek Wilk wrote:
> On Mar 5, 2014 5:46 PM, Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com> wrote:
>> On 3/5/2014 3:09 PM, Konrad Rzeszutek Wilk wrote:
>>> This patch fixes it and allows us to use AMT again by zeroing
>>> out io_base to zero. If the scan did not work, the io_base is
>>> set back to a default value.
>> If you provide 'amt' on command line => 'skip_amt' = 0
>> Then we'd just return -1 without setting io_base to 0x3f8 due to this
>> condition-
>> if ( !skip_amt )
>>      return -1;
>>
>> (or am I missing something?)
> That particular piece of code is executed after the loop. In the loop is where the AMT is found.
>>>     +    uart->io_base = 0;
>> Why not set ns16550.io_base = 0; in arch/x86/setup.c ?
> Because then you would break the default COM ports which are not find via PCI scanning.
>
> Say: com1=9600,8n1
>
> Which will use by default the 3f8 io base.

Ah. Okay, I see it now..
Thanks for the clarifications.

-Aravind.