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Subject: Re: [PATCH v2 4/4] ARM: dts: keystone: Add "ti,da830-uart" compatible
 string
To: David Lechner <david@lechnology.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Sekhar Nori <nsekhar@ti.com>, Santosh Shilimkar <ssantosh@kernel.org>
References: <1483561814-21953-1-git-send-email-david@lechnology.com>
 <1483561814-21953-5-git-send-email-david@lechnology.com>
Cc: Franklin S Cooper Jr <fcooper@ti.com>,
        Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>,
        Kevin Hilman <khilman@kernel.org>, Axel Haslam <ahaslam@baylibre.com>,
        Alexandre Bailon <abailon@baylibre.com>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Jiri Slaby <jslaby@suse.com>, linux-serial@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
From: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Organization: Oracle Corporation
Message-ID: <93c4aed0-6faa-2c27-7931-454fc1f48e79@oracle.com>
Date: Wed, 4 Jan 2017 14:00:01 -0800
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On 1/4/2017 12:30 PM, David Lechner wrote:
> The TI Keystone SoCs have extra UART registers beyond the standard 8250
> registers, so we need a new compatible string to indicate this. Also, at
> least one of these registers uses the full 32 bits, so we need to specify
> reg-io-width in addition to reg-shift.
>
> "ns16550a" is left in the compatible specification since it does work as
> long as the bootloader configures the SoC UART power management registers.
>
NAK!!
We can't break the booting boards with existing boot loaders.
I suggest you to first get the driver updated to take care of
the UART PM register and then enable the support for it.