On Thu, Oct 03, 2013 at 08:17:40PM +0200, Uwe Kleine-König wrote:
> Hello,
>
> there is only a single concern left and probably only the Freescale guys
> can comment here ...
> On Thu, Oct 03, 2013 at 09:32:04AM +0200, Hector Palacios wrote:
> > The shutdown function was not waiting for the FIFO (which may be the
> > real 16 byte FIFO or the DMA buffer, if DMA is enabled) to flush
> > before disabling the AUART.
> > This lead to many bytes not being transferred (specially at low
> > baudrates), as they were still in the DMA buffer when the AUART was
> > shutdown.
> > This patch also adds the check for the BUSY flag on the tx_empty
> > callback.
> >
> > Signed-off-by: Hector Palacios <hector.palacios@xxxxxxxx>
> > ---
> > drivers/tty/serial/mxs-auart.c | 25 +++++++++++++++++--------
> > 1 file changed, 17 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
> > index 9f046177..30edb91 100644
> > --- a/drivers/tty/serial/mxs-auart.c
> > +++ b/drivers/tty/serial/mxs-auart.c
> > @@ -757,9 +757,26 @@ static int mxs_auart_startup(struct uart_port *u)
> > return 0;
> > }
> >
> > +static unsigned int mxs_auart_tx_empty(struct uart_port *u)
> > +{
> > + unsigned long stat;
> > +
> > + stat = readl(u->membase + AUART_STAT);
> > + if ((stat & (AUART_STAT_BUSY | AUART_STAT_TXFE)) == AUART_STAT_TXFE)
> > + return TIOCSER_TEMT;
> Can it happen that both the fifo and the shifter are empty but there are
> still some chars pending to be transfered via DMA? If you were checking
> if dma is still setup you'd be on the safe side.
I'm deleting this from my queue until this gets resolved. Someone
please resend it when it does.
thanks,
greg k-h
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