Re: [PATCH v2 08/11] spi: cadence-qspi: add early busywait to cqspi_wait_for_bit()

Mark Brown
2024-04-08T16:40:38Z

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On Mon, Apr 08, 2024 at 04:42:43PM +0200, Théo Lebrun wrote:
> On Mon Apr 8, 2024 at 4:16 PM CEST, Mark Brown wrote:
> > On Fri, Apr 05, 2024 at 05:02:18PM +0200, Théo Lebrun wrote:

> > > The reason is to avoid hrtimer interrupts on the system. All read
> > > operations take less than 100µs.

> > Why would this be platform specific, this seems like a very standard
> > optimisation technique?

> It does not make sense if you know that all read operations take more
> than 100µs. I preferred being conservative. If you confirm it makes
> sense I'll remove the quirk.

It does seem plausible at least, and the time could be made a tuneable
with quirks or otherwise if that's needed. I think I'd expect the MIPS
platform you're working with to be towards the lower end of performance
for systems that are new enough to have this hardware.

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