Hi, Roger Quadros <[email protected]> writes: >> Roger Quadros <[email protected]> writes: >>>>> @@ -497,8 +503,8 @@ static int dwc3_omap_probe(struct platform_device >>>>> *pdev) >>>>> /* check the DMA Status */ >>>>> reg = dwc3_omap_readl(omap->base, USBOTGSS_SYSCONFIG); >>>>> >>>>> - ret = devm_request_irq(dev, omap->irq, dwc3_omap_interrupt, 0, >>>>> - "dwc3-omap", omap); >>>>> + ret = devm_request_threaded_irq(dev, omap->irq, dwc3_omap_interrupt, >>>>> + NULL, 0, "dwc3-omap", omap); >>>> >>>> if you're using threaded_irq, it's better to have a NULL top half and >>>> valid bottom half. >>> >>> But in this case we don't need a bottom half as there is nothing to do :). >>> >>>> >>>> In fact, since this will be shared, you could do a proper preparation >>>> and on top half check if $this device generated the IRQ and >>>> conditionally schedule the bottom half. Don't forget to mask device's >>>> interrupts from top half so you can run without IRQF_ONESHOT. >>>> >>> >>> Why do this at all if there is nothing to do in the bottom half? >> >> oh, but there is :-) >> >> The whole idea of threaded IRQs is that you spend as little time as >> possible on top half and the (strong) recommendation is that you *only* >> check if $this device generated the interrupt. Note that "checking if >> $this device generated the interrupt" will be mandatory as soon as you >> mark the IRQ line as shared ;-) >> >> So here's how this should look like: >> >> static irqreturn_t dwc3_omap_interrupt(int irq, void *_omap) >> { >> struct dwc3_omap *omap = _omap; >> u32 reg; >> >> reg = readl(IRQSTATUS) >> if (reg) { >> mask_interrupts(omap); >> return IRQ_WAKE_THREAD; >> } >> >> return IRQ_HANDLED; > > This should be IRQ_NONE right?
possibly, testing will say ;-)
>> static irqreturn_t dwc3_omap_threaded_interrupt(int irq, void *_omap)
>> {
>> struct dwc3_omap *omap = _omap;
>> u32 reg;
>>
>> spin_lock(&omap->lock);
>
> Do we really need a spin_lock for the dwc3-omap driver?
> Currently we won't be doing anything other than just
> clearing the irqstatus and re-enabling the interrupts.
well, if there's no possibility of races, then no. But only testing will
say for sure, I guess. I didn't really go through the entire thing just
to a write a quick little template :-p
--
balbi
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