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Subject: Re: [PATCH 2/3] ACPI: SPCR: Add support for AMD CT/SZ
To:     Daniel Kurtz <djkurtz@chromium.org>
Cc:     adurbin@chromium.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Len Brown <lenb@kernel.org>,
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Newsgroups: gmane.linux.kernel,gmane.linux.acpi.devel
References: <20180314003655.12141-1-djkurtz@chromium.org>
 <20180314003655.12141-3-djkurtz@chromium.org>
From:   Jon Masters <jcm@jonmasters.org>
Organization: World Organi{s,z}ation of Broken Dreams
Message-ID: <01bc6f27-57aa-d8e9-934b-191a128543cf@jonmasters.org>
Date:   Mon, 16 Apr 2018 20:43:46 -0400
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On 03/13/2018 08:36 PM, Daniel Kurtz wrote:
> AMD Carrizo / Stoneyridge use a DesignWare 8250 UART that uses a special
> earlycon setup handler to configure its input clock in order to compute
> baud rate divisor registers.
> Detect them by examining the OEMID field in the SPCR header, and pass
> then pass uart type amdcz to earlycon.

FYI I spoke with Microsoft some time ago about standardizing the ability
to convey non-standard baud rates in the SPCR. If you're interested in
driving, I can put you in touch with the right person over there.

Jon.

-- 
Computer Architect