From 46ffba0622f7171208fa2ec9d9d4ddc51c9ae1b4 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Mon, 1 Mar 2021 16:57:53 +0000 Subject: [PATCH] staging: comedi: dt2814: Don't wait for conversion in interrupt handler When the interrupt handler decides the final sample has been acquired, it turns off the timer enable (ENB) bit in the Command register. That triggers another A/D conversion. The interrupt handler currently waits for that to finish and then reads the resulting, unwanted sample. Since the functions for handling Comedi read instructions and for setting up asynchronous commands now call `dt2814_ai_clear()` to wait for and discard any spurious A/D conversion, let's remove that code from the interrupt handler. Signed-off-by: Ian Abbott Link: https://lore.kernel.org/r/20210301165757.243065-3-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/dt2814.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/staging/comedi/drivers/dt2814.c b/drivers/staging/comedi/drivers/dt2814.c index 7e73aa094eea2..8a70b7ba30f46 100644 --- a/drivers/staging/comedi/drivers/dt2814.c +++ b/drivers/staging/comedi/drivers/dt2814.c @@ -238,21 +238,13 @@ static irqreturn_t dt2814_interrupt(int irq, void *d) inb(dev->iobase + DT2814_DATA); if (!(--devpriv->ntrig)) { - int i; - outb(0, dev->iobase + DT2814_CSR); /* - * note: turning off timed mode triggers another - * sample. + * Note: turning off timed mode triggers another + * sample. This will be mopped up by the calls to + * dt2814_ai_clear(). */ - for (i = 0; i < DT2814_TIMEOUT; i++) { - if (inb(dev->iobase + DT2814_CSR) & DT2814_FINISH) - break; - } - inb(dev->iobase + DT2814_DATA); - inb(dev->iobase + DT2814_DATA); - s->async->events |= COMEDI_CB_EOA; } comedi_handle_events(dev, s); -- 2.30.2