On Fri, Aug 16, 2013 at 11:14:09AM +0200, Sebastian Andrzej Siewior wrote:
> * Zubair Lutfullah | 2013-08-13 17:48:18 [+0100]:
> >+ if ((status & IRQENB_FIFO0OVRRUN) ||
> >+ (status & IRQENB_FIFO0UNDRFLW)) {
> >+
> >+ config = titsc_readl(ts_dev, REG_CTRL);
> >+ config &= ~(CNTRLREG_TSCSSENB);
> >+ titsc_writel(ts_dev, REG_CTRL, config);
> >+
> >+ if (status & IRQENB_FIFO0UNDRFLW) {
> >+ titsc_writel(ts_dev, REG_IRQSTATUS,
> >+ (status | IRQENB_FIFO0UNDRFLW));
> >+ irqclr |= IRQENB_FIFO0UNDRFLW;
> >+ } else {
> >+ titsc_writel(ts_dev, REG_IRQSTATUS,
> >+ (status | IRQENB_FIFO0OVRRUN));
> >+ irqclr |= IRQENB_FIFO0OVRRUN;
> >+ }
>
> You don't do anything on overflow / underflow. Is this due to the fact
> once enabled for FIFO1 it also triggers for FIFO0?
>
The TSCADC module doesn't recover from these interrupts.
> >+ titsc_writel(ts_dev, REG_CTRL,
> >+ (config | CNTRLREG_TSCSSENB));
The fix is to re-enable the module after disabling
and clearing the interrupts.
That is what the handler is doing.
> >+ } else if (status & IRQENB_FIFO0THRES) {
> > titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
> >
> > if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
> >@@ -317,9 +342,11 @@ static irqreturn_t titsc_irq(int irq, void *dev)
> > }
> >
> > if (irqclr) {
> >- titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
> >+ titsc_writel(ts_dev, REG_IRQSTATUS, (status | irqclr));
>
> Shouldn't FIFO1UNDRFLW & OVRRUN be handled by the adc driver? Why do you
> or the unhandled bits as well here?
FIFO1 is only used by TSC. ADC doesn't touch it.
>
> > am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask);
> >- return IRQ_HANDLED;
> >+ status = titsc_readl(ts_dev, REG_IRQSTATUS);
> >+ if (status == false)
> >+ return IRQ_HANDLED;
>
> And why this? If you something you handled it, if you didn't you return
> NONE. Why does it depend on REG_IRQSTATUS?
These quirks are to handle the situation where both IRQs happen
simultaneously. Which can occur when someone is using the TSC
while continuously sampling using the ADC.
REG_IRQSTATUS has flags for FIFO0 used by ADC as well.
If there are still those IRQs to handle, then IRQ_NONE is returned.
Otherwise, all IRQ flags are clear so IRQ_HANDLED is returned.
Thanks
Zubair
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