Re: [GIT PULL 1/2] bcm2835-dt-fixes-2017-10-06

From: Marcel Holtmann <marcel@holtmann.org>
To: Peter Robinson <pbrobinson@gmail.com>
Cc: Stefan Wahren <stefan.wahren@i2se.com>,
	Matt Hart <matt@mattface.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	bcm-kernel-feedback-list@broadcom.com,
	linux-rpi-kernel@lists.infradead.org,
	Loic Poulain <loic.poulain@gmail.com>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Eric Anholt <eric@anholt.net>
Subject: Re: [GIT PULL 1/2] bcm2835-dt-fixes-2017-10-06
Date: Wed, 1 Nov 2017 13:16:42 +0100	[thread overview]
Message-ID: <F3464528-76E5-4F11-BD58-DEB56410687B@holtmann.org> (raw)
In-Reply-To: <CALeDE9Oi+DvoJ6X22ButaQxHNyqBzg=H1-mb69_g-rp4RR_fqw@mail.gmail.com>

Hi Peter,

>>>>>> Hi Florian.  Here's a patch that's gone through a couple of revisions
>>>>>> on the list, that seriously fixes up the default serial behavior --
>>>>>> previously, without the right config.txt/cmdline bits, you'd often end
>>>>>> up with a hang with no output before booting completed.  It would be
>>>>>> great to get it into 4.14.
>>>>>> 
>>>>>> The following changes since commit 2bd6bf03f4c1c59381d62c61d03f6cc3fe71f66e:
>>>>>> 
>>>>>>  Linux 4.14-rc1 (2017-09-16 15:47:51 -0700)
>>>>>> 
>>>>>> are available in the git repository at:
>>>>>> 
>>>>>>  git://github.com/anholt/linux tags/bcm2835-dt-fixes-2017-10-06
>>>>>> 
>>>>>> for you to fetch changes up to f08f58a2bf68900a84e782b8c7ad701c0654173c:
>>>>>> 
>>>>>>  ARM: dts: bcm283x: Fix console path on RPi3 (2017-10-06 13:04:56 -0700)
>>>>>> 
>>>>>> ----------------------------------------------------------------
>>>>>> This pull request brings in a fix for default serial console setup on
>>>>>> RPi3, so it now comes up with no config.txt/cmdline.txt settings in
>>>>>> the firmware.
>>>>>> 
>>>>>> ----------------------------------------------------------------
>>>>> Merged, thanks Eric
>>>>> 
>>>>> --
>>>>> Florian
>>>> Hi all,
>>>> 
>>>> I realise this patch has been in mainline for a more than a week, but
>>>> I've only recently had time to bisect broken rpi-3 boots in kernelci
>>>> and found f08f58a2bf68900a84e782b8c7ad701c0654173c as the cause.
>>>> 
>>>> Kernelci boots the rpi3 using uboot, with console=ttyS0 in the command
>>>> line which now fails:
>>>> https://kernelci.org/boot/id/59f787f059b5147794ef1dcf/
>>>> 
>>>> Is there an alias I can use for both before and after this patch?
>>>> 
>>>> Mainline boots fine if I use console=ttyS1 or drop the console arg
>>>> altogether, but as we don't currently support different boot args per
>>>> tree, and we don't have the manpower to track this patch in all the
>>>> trees we test, we will have to switch to only boot testing mainline
>>>> from now on.
>>> Yes, I've seen the same in Fedora with that patch.
>>> 
>>> 
>> could you please describe the issue more in detail.
>> 
>> Does u-boot or Linux hang? Does u-boot select the wrong UART? Is there a
>> pinmux conflict?
> 
> Basically on the RPi3 you use to get ttyAMA0 and ttyS0 but now the
> later is ttyS1

which UART is which now. It should expose the Bluetooth UART correctly now. And also more importantly usable. The only missing piece with 4.14 would be the DT assigned for serdev. While 4.14 would still require a call to btattach, starting with 4.15 that should no longer be needed.

Regards

Marcel