Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <9ef45899-c766-e839-522a-3b048f8106f7@kernel.org>
Date:   Mon, 3 Jul 2023 16:44:14 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [PATCH 0/3] Configure usb0 as peripheral on am335x boards
Content-Language: en-US
To:     Julien Panis <jpanis@baylibre.com>,
        Tony Lindgren <tony@atomide.com>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>, linux-omap@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        vigneshr@ti.com, nm@ti.com
References: <20230629-usb0-as-peripheral-v1-0-167f78a11746@baylibre.com>
 <20230630072047.GK14287@atomide.com>
 <f4fa80fd-1a6a-4718-0287-f5288cd9d912@baylibre.com>
 <7f44798b-e2bf-1620-da37-ca13bfd07a21@kernel.org>
 <babf5f20-ddf4-74bf-1788-f8e356acaa92@baylibre.com>
From:   Roger Quadros <rogerq@kernel.org>
In-Reply-To: <babf5f20-ddf4-74bf-1788-f8e356acaa92@baylibre.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk


On 03/07/2023 14:56, Julien Panis wrote:
> On 6/30/23 21:40, Roger Quadros wrote:
>> Hi,
>>
>> On 30/06/2023 11:30, Julien Panis wrote:
>>> Hello Tony,
>>>
>>> On 6/30/23 09:20, Tony Lindgren wrote:
>>>> Hi,
>>>>
>>>> * Julien Panis <jpanis@baylibre.com> [230629 13:10]:
>>>>> This series configures usb0 dr_mode as 'peripheral' for am335x-evm,
>>>>> am335x-evmsk, and am335x-icev2. This USB port is mainly used for
>>>>> RNDIS and DFU.
>>>> Is this a mini-B connector? Just wondering if it was originally attempted
>>>> to be configured as OTG or how it ended up with a host configuration..
>>> It's a micro USB-AB connector.
>>> I don't know how it ended up with a host configuration, it looks like an oversight.
>>> Maybe Vignesh or Nishanth can confirm (?)
>> usb0 role should be "otg".
>> It is rightly so in Linux DT. am33xx.dtsi contains "otg" and all AM335x board files inherit from it.
>>
>> So I don't think setting it to "peripheral" in u-boot is the right thing to do.
> 
> This series is for kernel (not for u-boot).
> Why is it a problem to set usb0 as 'peripheral' in kernel for the 3 board dts ?
> 
> With usb0 not set as 'peripheral', the 3 boards (am335x-evm, evm-sk, icev2)
> do not boot with uboot 2023.04. This error is returned, with LOG_LEVEL=5:
>     No USB device found
>     USB ether init failed
>     initcall sequence 8ffdbba4 failed at call 808024d9 (err=-19)
>     ### ERROR ### Please RESET the board ###
> This error is also returned with usb0 as 'otg'.

This error is at u-boot correct? This will need further investigation.

Does it function correctly in Linux when kept as 'otg'?

-- 
cheers,
-roger