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Date:   Wed, 26 Jan 2022 15:21:29 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Phil Elwell <phil@raspberrypi.com>
Cc:     Wander Lairson Costa <wander@redhat.com>,
        Johan Hovold <johan@kernel.org>,
        "Maciej W. Rozycki" <macro@orcam.me.uk>,
        Lukas Wunner <lukas@wunner.de>,
        Florian Fainelli <f.fainelli@gmail.com>,
        linux-serial@vger.kernel.org, linux-rpi-kernel@lists.infradead.org
Subject: Re: [PATCH] serial: 8250: Fix ...console_fifo_write on BCM283x
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References: <20220126141124.4086065-1-phil@raspberrypi.com>
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On Wed, Jan 26, 2022 at 02:11:24PM +0000, Phil Elwell wrote:
> The mini-UART on BCM283x is doubly crippled - it has 8-byte FIFOs and
> the THRE bit indicates that the TX FIFO is not-full rather than empty.
> 
> The optimisation to enable the use of the FIFO assumes that it is safe
> to write fifosize bytes whenever THRE is set, but the BCM283x quirk
> (indicated by the presence of UART_CAP_MINI) makes it necessary to
> check the FIFO state after each byte.
> 
> See: https://github.com/raspberrypi/linux/issues/4849
> 
> Fixes: 5021d709b31b ("tty: serial: Use fifo in 8250 console driver")

I have just reverted this commit, it's broken for many platforms now,
not just yours.

So there shouldn't be a need for this change now, right?

thanks,

greg k-h