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Message-ID: <7f44798b-e2bf-1620-da37-ca13bfd07a21@kernel.org>
Date:   Fri, 30 Jun 2023 22:40:19 +0300
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Subject: Re: [PATCH 0/3] Configure usb0 as peripheral on am335x boards
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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>
From:   Roger Quadros <rogerq@kernel.org>
In-Reply-To: <f4fa80fd-1a6a-4718-0287-f5288cd9d912@baylibre.com>
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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.

> 
>>
>>> Initially, a series was submitted to overlay dr_mode in u-boot specific
>>> device trees ('<board>-u-boot.dtsi'):
>>> https://lore.kernel.org/all/20230621-fix_usb_ether_init-v2-0-ff121f0e8d7a@baylibre.com/
>>>
>>> It was finally decided to modify linux device trees.
>> Do we need these as fixes? If so is there a fixes tag for these?
> 
> I don't think so.
> The u-boot series mentioned above was submitted to fix an error returned
> by usb_ether_init() function. This error appeared after changes in u-boot
> (arch/arm/mach-omap2/am33xx/board.c). The u-boot commit is:
> 6815a66ad7430 ("am33xx: musb: Remove unused configuration logic").
> But this commit is right actually, and the error appeared because dr_mode
> was not properly configured for am335x-evmsk and am335x-icev2 dts.
> In other words, this u-boot commit is correct but revealed an oversight
> in dr_mode configuration for these boards.
> So, there is not a fixes tag here. That was just an omission in device trees.
> 
>>
>> Regards,
>>
>> Tony
> 
> Julien
> 

-- 
cheers,
-roger