RE: [PATCH] SPI: Add driver for Cadence SPI controller

[Harini Katakam]

HI Mark,

> -----Original Message-----
> From: Mark Brown [mailto:broonie@xxxxxxxxxx]
> Sent: Tuesday, March 18, 2014 6:04 PM
> To: Harini Katakam
> Cc: robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx; mark.rutland@xxxxxxx;
> ijc+devicetree@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx; rob@xxxxxxxxxxx;
> grant.likely@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> doc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> spi@xxxxxxxxxxxxxxx; Michal Simek
> Subject: Re: [PATCH] SPI: Add driver for Cadence SPI controller
> 
> On Tue, Mar 18, 2014 at 12:13:45PM +0000, Harini Katakam wrote:
> 
> 
> > > > In this case both possible interrupt conditions are handled.
> 
> > > Are you sure that's the case, and even if you are that's still not
> > > handling the case where the device isn't flagging an interrupt at all.
> 
> > The IXR_ALL mask is only used to disable all the interrupts in the
> beginning.
> > These two are the only interrupts enabled.
> > And RXNEMPTY status is just polled. That interrupt is not enabled either
> 
> This is all going to be fragile in the face of bugs or changes in the
> code though and like I keep saying it doesn't handle interrupt sharing.

OK. I dint consider interrupt sharing. 
Do you think the following implementation would be better?

status = IRQ_NONE;
if (intr_status & CDNS_SPI_IXR_MODF_MASK) {
	/* Handle this interrupt here */
	status = IRQ_HANDLED;
} else if (intr_status & CDNS_SPI_IXR_TXOW_MASK) {
	/* Handle this interrupt here */
	status = IRQ_HANDLED;
}

return status;

Regards,
Harini


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