On Fri, Feb 28, 2014 at 03:33:11PM +0200, Andy Shevchenko wrote:

On Fri, 2014-02-28 at 11:36 +0100, Maxime Ripard wrote:

quoted

Hi Andy,

On Tue, Feb 25, 2014 at 01:28:15PM +0200, Andy Shevchenko wrote:

quoted

quoted

+static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
+{
+	struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)dev_id;
+	struct sun6i_vchan *vchan;
+	struct sun6i_pchan *pchan;
+	int i, j, ret = 0;
+	u32 status;
+
+	for (i = 0; i < 2; i++) {
+		status = readl(sdev->base + DMA_IRQ_STAT(i));
+		if (!status) {
+			ret |= IRQ_NONE;

Maybe move this to definition block.

quoted

+			continue;
+		}
+
+		dev_dbg(sdev->slave.dev, "DMA irq status %s: 0x%x\n",
+			i ? "high" : "low", status);
+
+		writel(status, sdev->base + DMA_IRQ_STAT(i));
+
+		for (j = 0; (j < 8) && status; j++) {
+			if (status & DMA_IRQ_QUEUE) {
+				pchan = sdev->pchans + j;
+				vchan = pchan->vchan;
+
+				if (vchan) {
+					unsigned long flags;
+
+					spin_lock_irqsave(&vchan->vc.lock,
+							  flags);
+					vchan_cookie_complete(&pchan->desc->vd);
+					pchan->done = pchan->desc;
+					spin_unlock_irqrestore(&vchan->vc.lock,
+							       flags);
+				}
+			}
+
+			status = status >> 4;
+		}
+
+		ret |= IRQ_HANDLED;

In case one is handled, another is not, what you have to do?

The interrupt status is split across two registers. In the case where
one of the two register reports an interrupt, we still have to handle
our interrupt, we actually did, so we have to return IRQ_HANDLED.

You removed the code below this assignment, but if I remember correctly
you check for exact value there.

In case of one is not handled and the other is handled you will have ret
= IRQ_HANDLED | IRQ_NONE. Thus, your following code will not be
executed. Is it by design?

The code that got removed was

if (ret == IRQ_HANDLED)
   tasklet_schedule()

return ret;

The only thing that wouldn't have been executed if we had no
interrupts to report was the tasklet_schedule.

This has lightly changed though in the v2, thanks to your comments.

I don't have the | anymore, and call tasklet_schedule directly in the
loop.

I'll send the v2 in a short while.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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