[alsa-devel] [PATCH v3 1/2] ASoC: cs35l33: Initial commit of the cs35l33 CODEC driver.

Mark Brown broonie at kernel.org
Mon May 16 19:06:14 CEST 2016


On Mon, May 16, 2016 at 10:20:24AM -0500, Paul Handrigan wrote:
> On Fri, 13 May 2016, Mark Brown wrote:
> > On Fri, May 13, 2016 at 03:50:28PM -0500, Paul.Handrigan at cirrus.com wrote:

> > > +	for (i = 0; i < CS35L33_INT_ATTEMPTS; i++) {
> > > +		/* ack the irq by reading both status registers */

> > Why do we need this...?

> The we need to keep handling the unmasked interrupts until they are
> all cleared.  We could get another interrupt while handling the first
> triggered interrupt, but the interrupt line could be de-asserted due to
> the read-to-clear nature of the interrupt status registers.

This doesn't follow?  Clear to read shouldn't be affected by reading
repeatedly, or at least I don't see that helps any problems in a
non-racy fashion, and the interrupt subsystem will happily call the
handler again if the interrupt reasserts during handling so new
interrupts shouldn't be an issue either.  New interrupts are an issue
for most devices so we really ought to have handling for that in the
interrupt subsystem if it's needed, or possibly the usage of the
subsystem needs to change to take advantage of preexisting handling...
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