Hi John, On 01/22/2016 02:27 AM, John Ogness wrote: > It has been seen that spurious interrupts are generated when the > DMA engine is in use. By disabling timeout interrupts (~IER_RDI) > this phenomenon goes away, but this driver relies on the timeout > interrupts, so we just consume the spurious interrupts. > > Since we are consuming spurious interrupts, the irq cannot be > shared with other drivers. (It is never really shared anyway.) Does this fix the spurious irqs referred to by Sekhar in this email chain https://lkml.org/lkml/2015/12/3/442 ? > Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx> > --- > patch against next-20160122 > > drivers/tty/serial/8250/8250_omap.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c > index ef7a60b..004b85a 100644 > --- a/drivers/tty/serial/8250/8250_omap.c > +++ b/drivers/tty/serial/8250/8250_omap.c > @@ -630,7 +630,7 @@ static int omap_8250_startup(struct uart_port *port) > } > #endif > > - ret = request_irq(port->irq, omap8250_irq, IRQF_SHARED, > + ret = request_irq(port->irq, omap8250_irq, 0, > dev_name(port->dev), port); > if (ret < 0) > goto err; > @@ -1112,8 +1112,14 @@ static int omap_8250_dma_handle_irq(struct uart_port *port, unsigned int iir) > unsigned char status; > int dma_err; > > + /* > + * It has been seen that spurious interrupts are generated when the > + * DMA engine is in use. By disabling timeout interrupts (~IER_RDI) > + * this phenomenon goes away, but this driver relies on the timeout > + * interrupts, so we just consume the spurious interrupts. > + */ > if (iir & UART_IIR_NO_INT) > - return 0; > + return 1; > > spin_lock(&port->lock); > > -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
