On Mon, Aug 10, 2015 at 08:31:03PM -0400, Peter Hurley wrote:
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 2af09ab..fd54991 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2348,13 +2348,10 @@ static struct console amba_console = {
>
> static void pl011_putc(struct uart_port *port, int c)
> {
> - struct uart_amba_port *uap =
> - container_of(port, struct uart_amba_port, port);
> -
> - while (pl011_readw(uap, REG_FR) & UART01x_FR_TXFF)
> + while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
> ;
> - pl011_writeb(uap, c, REG_DR);
> - while (pl011_readw(uap, REG_FR) & uap->fr_busy)
> + writeb(c, port->membase + UART01x_DR);
> + while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
> ;
These loops are wrong. Kernel coding style is that loops like this
will use cpu_relax() in them, just like the driver used to. This
was introduced by:
commit 0d3c673e7881e691991b2a4745bd4f149603baa2
Author: Rob Herring <robh@xxxxxxxxxx>
Date: Fri Apr 18 17:19:57 2014 -0500
tty/serial: pl011: add generic earlycon support
Also, the above readl()s should be readl_relaxed(), we don't need
barriered reads or to hit the L2 cache on those reads in the above code.
--
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
