[RFC] tty: pl011: Work around stuck BUSY bit on QDF2400

[Russell King - ARM Linux]

On Mon, Jan 30, 2017 at 06:44:17PM -0500, Christopher Covington wrote:
>  {
>  	struct uart_amba_port *uap =
>  	    container_of(port, struct uart_amba_port, port);
> -	unsigned int status = pl011_read(uap, REG_FR);
> +	unsigned int status = pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr;
>  	return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ?
>  							0 : TIOCSER_TEMT;
>  }

I'd much prefer the reg & mask == val approach, but the above makes that
difficult.

So for the PL011 changes:

Acked-by: Russell King <rmk+kernel at armlinux.org.uk>

Thanks.

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