Re: [BISECTED] arm: dts: Resync BeagleBone device trees

From: Harald Seiler <hws@denx.de>
To: Peter Robinson <pbrobinson@gmail.com>
Cc: "Matwey V. Kornilov" <matwey.kornilov@gmail.com>,
	U-Boot Mailing List <u-boot@lists.denx.de>,
	paul.barker@sancloud.com, Tom Rini <trini@konsulko.com>
Subject: Re: [BISECTED] arm: dts: Resync BeagleBone device trees
Date: Fri, 06 Aug 2021 14:21:01 +0200	[thread overview]
Message-ID: <023dd4d80d17e2c3a3cf9eb2784d243d3a83c744.camel@denx.de> (raw)
In-Reply-To: <CALeDE9ObPuECU3BU4BEF5UWYy_Gq-4a3jMR+jScmjpurq8=Q0Q@mail.gmail.com>

On Fri, 2021-08-06 at 12:44 +0100, Peter Robinson wrote:
> On Fri, Aug 6, 2021 at 12:39 PM Harald Seiler <hws@denx.de> wrote:
> > 
> > Hi,
> > 
> > On Fri, 2021-08-06 at 13:54 +0300, Matwey V. Kornilov wrote:
> > > Hello,
> > > 
> > > I've found that the following commit breaks USB on BeagleBone Black
> > > board (am335x based):
> > > 
> > > commit 942853dd96df5de1c0a2a61c877c1cf1c24f1e91
> > > Author: Paul Barker <paul.barker@sancloud.com>
> > > Date:   Mon Jul 12 21:14:09 2021 +0100
> > > 
> > >     arm: dts: Resync BeagleBone device trees
> > > 
> > > 
> > > When commit is applied then I see the following:
> > > 
> > > starting USB...
> > > No working controllers found
> > > USB is stopped. Please issue 'usb start' first.
> > > starting USB...
> > > No working controllers found
> > > 
> > > Before the commit USB was working as expected:
> > > 
> > > starting USB...
> > > Bus usb@47401800: scanning bus usb@47401800 for devices... 1 USB Device(s) found
> > >        scanning usb for storage devices... 1 Storage Device(s) found
> > > 
> > > Device 0: Vendor:          Rev: PMAP Prod: USB DISK Pro
> > >             Type: Removable Hard Disk
> > >             Capacity: 7381.2 MB = 7.2 GB (15116736 x 512)
> > > ... is now current device
> > 
> > It looks the the arch/arm/dts/am33xx.dtsi file is out of sync with
> > Linux, leading to this regression.  In the current U-Boot version, it
> > has
> > 
> >         status = "disabled";
> > 
> > lines for e.g. usb0 while in Linux mainline, those are missing.  As the
> > commit you found by bisecting drops the
> > 
> >         status = "okay";
> > 
> > lines from arch/arm/dts/am335x-bone-common.dtsi, the device now are no
> > longer enabled.  Maybe try syncing am33xx.dtsi as well to check if it
> > helps?
> 
> It's usual for peripheral devices to be disabled in the SoC .dtsi
> file, those that are actively used by devices are supposed to enable
> them in the device .dts so I would expect to see the appropriate bit
> enabling it in the device .dts.

True, but apparently this was changed for am33xx.dtsi, see Linux commit
0782e8572ce4 ("ARM: dts: Probe am335x musb with ti-sysc") [1].

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0782e8572ce43f521ed6ff15e4a7ab9aa5acdc85

-- 
Harald

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-62  Fax: +49-8142-66989-80   Email: hws@denx.de