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From:   Brendan Higgins <brendanhiggins@google.com>
Date:   Sun, 27 Dec 2020 12:00:19 -0800
Message-ID: <CAFd5g45i-x5itqnLQe1tikSVsycF8HZcJiiKiJ-SRo4D7b9dxQ@mail.gmail.com>
Subject: Re: [PATCH] kunit: tool: Force the use of the 'tty' console for UML
To:     David Gow <davidgow@google.com>
Cc:     Petr Mladek <pmladek@suse.com>,
        Shuah Khan <skhan@linuxfoundation.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        KUnit Development <kunit-dev@googlegroups.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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On Mon, Dec 21, 2020 at 11:39 PM David Gow <davidgow@google.com> wrote:
>
> kunit_tool relies on the UML console outputting printk() output to the
> tty in order to get results. Since the default console driver could
> change, pass 'console=tty' to the kernel.
>
> This is triggered by a change[1] to use ttynull as a fallback console
> driver which -- by chance or by design -- seems to have changed the
> default console output on UML, breaking kunit_tool. While this may be
> fixed, we should be less fragile to such changes in the default.
>
> [1]:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e
>
> Signed-off-by: David Gow <davidgow@google.com>
> Fixes: 757055ae8ded ("init/console: Use ttynull as a fallback when there is no console")

Acked-by: Brendan Higgins <brendanhiggins@google.com>

Thanks for taking care of this!