[PATCH] serial: 8250: Fix ...console_fifo_write on BCM283x

Greg Kroah-Hartman gregkh at linuxfoundation.org
Wed Jan 26 06:21:29 PST 2022

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?


greg k-h

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