Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 08 Apr 2024 16:42:43 +0200 | Subject | Re: [PATCH v2 08/11] spi: cadence-qspi: add early busywait to cqspi_wait_for_bit() | From | Théo Lebrun <> |
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Hello,
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: > > > If the CQSPI_BUSYWAIT_EARLY quirk flag is on, call > > readl_relaxed_poll_timeout() with no sleep at the start of > > cqspi_wait_for_bit(). If its short timeout expires, a sleeping > > readl_relaxed_poll_timeout() call takes the relay. > > > > Behavior is hidden behind a quirk flag to keep the previous behavior the > > same on all platforms. > > > > 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.
Regards,
-- Théo Lebrun, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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