Messages in this thread | | | Date | Mon, 10 Sep 2012 12:17:02 +0100 | From | Alan Cox <> | Subject | Re: [PATCH 09/14] tty/serial/amba-pl011: Implement clear_irqs callback |
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On Sun, 9 Sep 2012 21:14:04 -0700 Anton Vorontsov <anton.vorontsov@linaro.org> wrote:
> It's all pretty straightforward, except for TXIM interrupt. The interrupt > has meaning "ready to transmit", so it's almost always raised, and the > only way to silence it is to mask it. But that's OK, ops->start_tx will > unmask it. > > Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> > --- > drivers/tty/serial/amba-pl011.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c > index 88e2df2..7522d97 100644 > --- a/drivers/tty/serial/amba-pl011.c > +++ b/drivers/tty/serial/amba-pl011.c > @@ -1308,6 +1308,18 @@ static void pl011_put_poll_char(struct uart_port *port, > writew(ch, uap->port.membase + UART01x_DR); > } > > +static void pl011_clear_irqs(struct uart_port *port) > +{ > + struct uart_amba_port *uap = (struct uart_amba_port *)port; > + unsigned char __iomem *regs = uap->port.membase; > + > + writew(readw(regs + UART011_MIS), regs + UART011_ICR); > + /* > + * There is no way to clear TXIM, this is "ready to transmit IRQ", so > + * we simply mask it. ops->start_tx will unmask it. > + */
Not if you race here with the transmit start it won't.
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