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Message-ID: <f9f8f08d-4d49-11cb-484b-b5b1a434b0a9@phytec.de>
Date:   Thu, 31 Mar 2022 09:19:54 +0200
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Subject: Re: [RFC] arm64: dts: ti: introduce a minimal am642 device tree
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To:     Vignesh Raghavendra <vigneshr@ti.com>, Bryan Brattlof <bb@ti.com>,
        Nishanth Menon <nm@ti.com>, Tero Kristo <kristo@kernel.org>
CC:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzk+dt@kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20220321155417.13267-1-bb@ti.com>
 <73a4a16b-193a-3075-61e9-82bcf21fc7d2@phytec.de>
 <16ad1a82-1e99-2957-720f-08d1238edcf4@ti.com>
From:   Wadim Egorov <w.egorov@phytec.de>
In-Reply-To: <16ad1a82-1e99-2957-720f-08d1238edcf4@ti.com>
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Am 31.03.22 um 08:58 schrieb Vignesh Raghavendra:
> Hi Wadim,
> 
> On 30/03/22 7:25 pm, Wadim Egorov wrote:
>> Hi Bryan,
>>
>>> +/* (optional) for console */
>>> +&main_uart0 {
>>> +    pinctrl-names = "default";
>>> +    pinctrl-0 = <&main_uart0_pins_default>;
>>> +};
>>> +
>>> +/* reserved for firmware */
>>> +&main_uart1 {
>>> +    status = "reserved";
>>> +};
>>
>> k3-image-gen says UART0 is used as a debug interface. See
>>
>>
>> https://git.ti.com/cgit/k3-image-gen/k3-image-gen/tree/soc/am64x/evm/board-cfg.c#n81
>>
>>
>> So it seems that you can enable uart1 here. But people may run into a
>> conflict with uart0 and k3-image-gen compiled with ENABLE_TRACE=1.
>>
>> If I am wrong, can you please clarify why you mark uart1 as reserved.
>>
> 
> We just seem to have same macro shared across multiple SoCs,
> BOARDCFG_TRACE_DST_UART0 means logs are also directed to UART. Instance
> of UART used for logging is platform specific.
> 
> On AM64 SYSFW logs are directed to MAIN UART1 (MAIN UART0 is used for
> linux console). I will work internally and get SYSFW documentation
> updated to reflect the same. Thanks!

OK, thank you for the clarification.

> 
> Regards
> Vignesh